%%% -*-BibTeX-*-
%%% ====================================================================
%%% BibTeX-file{
%%% author = "Nelson H. F. Beebe",
%%% version = "1.57",
%%% date = "23 June 2017",
%%% time = "17:27:25 MDT",
%%% filename = "tocl.bib",
%%% address = "University of Utah
%%% Department of Mathematics, 110 LCB
%%% 155 S 1400 E RM 233
%%% Salt Lake City, UT 84112-0090
%%% USA",
%%% telephone = "+1 801 581 5254",
%%% FAX = "+1 801 581 4148",
%%% URL = "http://www.math.utah.edu/~beebe",
%%% checksum = "11729 17488 90524 872762",
%%% email = "beebe at math.utah.edu, beebe at acm.org,
%%% beebe at computer.org (Internet)",
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%%% the journal ACM Transactions on Computational
%%% Logic (no CODEN, ISSN 1529-3785), for
%%% 2000--date.
%%%
%%% Publication began with volume 1, number 1, in
%%% July 2000. The journal appears quarterly.
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%%% text of recent articles in PDF form.
%%%
%%% At version 1.57, the COMPLETE journal
%%% coverage looked like this:
%%%
%%% 2000 ( 12) 2006 ( 24) 2012 ( 34)
%%% 2001 ( 21) 2007 ( 31) 2013 ( 34)
%%% 2002 ( 18) 2008 ( 22) 2014 ( 34)
%%% 2003 ( 21) 2009 ( 36) 2015 ( 43)
%%% 2004 ( 23) 2010 ( 30) 2016 ( 25)
%%% 2005 ( 28) 2011 ( 21) 2017 ( 17)
%%%
%%% Article: 474
%%%
%%% Total entries: 474
%%%
%%% The initial draft of this bibliography was
%%% derived from data at the ACM Web site.
%%%
%%% ACM copyrights explicitly permit abstracting
%%% with credit, so article abstracts, keywords,
%%% and subject classifications have been
%%% included in this bibliography wherever
%%% available.
%%%
%%% The bibsource keys in the bibliography
%%% entries below indicate the data sources.
%%%
%%% URL keys in the bibliography point to
%%% World Wide Web locations of additional
%%% information about the entry.
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%%%
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%%% publication order, using ``bibsort -byvolume.''
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%%% Acknowledgement abbreviations:
@String{ack-nhfb = "Nelson H. F. Beebe,
University of Utah,
Department of Mathematics, 110 LCB,
155 S 1400 E RM 233,
Salt Lake City, UT 84112-0090, USA,
Tel: +1 801 581 5254,
FAX: +1 801 581 4148,
e-mail: \path|beebe@math.utah.edu|,
\path|beebe@acm.org|,
\path|beebe@computer.org| (Internet),
URL: \path|http://www.math.utah.edu/~beebe/|"}
%%% ====================================================================
%%% Journal abbreviations:
@String{j-TOCL = "ACM Transactions on Computational Logic"}
%%% ====================================================================
%%% Publisher abbreviations:
@String{pub-ACM = "ACM Press"}
@String{pub-ACM:adr = "New York, NY 10036, USA"}
%%% ====================================================================
%%% Bibliography entries:
@Article{Paulson:2000:MUI,
author = "Lawrence C. Paulson",
title = "Mechanizing {UNITY} in {Isabelle}",
journal = j-TOCL,
volume = "1",
number = "1",
pages = "3--32",
month = jul,
year = "2000",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Oct 13 11:28:38 MDT 2000",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/articles/journals/tocl/2000-1-1/p3-paulson/p3-paulson.pdf;
http://www.acm.org/pubs/citations/journals/tocl/2000-1-1/p3-paulson/",
abstract = "UNITY is an abstract formalism for proving properties
of concurrent systems, which typically are expressed
using guarded assignments [Chandy and Misra 1988].
UNITY has been mechanized in higher-order logic using
Isabelle, a proof assistant. Safety and progress
primitives, their weak forms (for the substitution
axiom), and the program composition operator (union)
have been formalized. To give a feel for the concrete
syntax, this article presents a few extracts from the
Isabelle definitions and proofs. It discusses a small
example, two-process mutual exclusion. A mechanical
theory of unions of programs supports a degree of
compositional reasoning. Original work on extending
program states is presented and then illustrated
through a simple example involving an array of
processes.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "compositional reasoning; concurrency; Isabelle;
UNITY",
subject = "Theory of Computation --- Logics and Meanings of
Programs --- Specifying and Verifying and Reasoning
about Programs (F.3.1)",
}
@Article{Libkin:2000:LCL,
author = "Leonid Libkin",
title = "Logics with counting and local properties",
journal = j-TOCL,
volume = "1",
number = "1",
pages = "33--59",
month = jul,
year = "2000",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Oct 13 11:28:38 MDT 2000",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/citations/journals/tocl/2000-1-1/p33-libkin/",
abstract = "The expressive power of first-order logic over finite
structures is limited in two ways: it lacks a recursion
mechanism, and it cannot count. Overcoming the first
limitation has been a subject of extensive study. A
number of fixpoint logics have been introduced. and
shown to be subsumed by an infinitary logic L w w. This
logic is easier to analyze than fixpoint logics, and it
still lacks counting power, as it has a 0-1 law. On the
counting side, there is no analog of L w w. There are a
number of logics with counting power, usually
introduced via generalized quantifiers. Most known
expressivity bounds are based on the fact that counting
extensions of first-order logic preserve the locality
properties. This article has three main goals. First,
we introduce a new logic L * w ( C ) that plays the
same role for counting as L w w does for recursion--it
subsumes a number of extensions of first-order logic
with counting, and has nice properties that make it
easy to study. Second, we give simple direct proof that
L w w ( C ) expresses only local properties: those that
depend on the properties of small neighborhoods, but
cannot grasp a structure as a whole. This is a general
way of saying that a logic lacks a recursion mechanism.
Third, we consider a finer analysis of locality of
counting logics. In particular, we address the question
of how local a logic is, that is, how big are those
neighborhoods that local properties depend on. We get a
uniform answer for a variety of logics between
first-order and L * w ( C ). This is done by
introducing a new form of locality that captures the
tightest condition that the duplicator needs to
maintain in order to win a game. We also use this
technique to give bounds on outputs of L * w
(C)-definable queries.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "counting; first-order logic; infinitary logic;
locality",
subject = "Theory of Computation --- Mathematical Logic and
Formal Languages --- Mathematical Logic (F.4.1)",
}
@Article{Kozen:2000:HLK,
author = "Dexter Kozen",
title = "On {Hoare} logic and {Kleene} algebra with tests",
journal = j-TOCL,
volume = "1",
number = "1",
pages = "60--76",
month = jul,
year = "2000",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Oct 13 11:28:38 MDT 2000",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/citations/journals/tocl/2000-1-1/p60-kozen/",
abstract = "We show that Kleene algebra with tests (KAT) subsumes
propositional Hoare logic (PHL). Thus the specialized
syntax and deductive apparatus of Hoare logic are
inessential and can be replaced by simple equational
reasoning. In addition, we show that all relationally
valid inference rules are derivable in KAT and that
deciding the relational validity of such rules is {\em
PSPACE}-complete.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "dynamic logic; Hoare logic; Kleene algebra; Kleene
algebra with tests; specification",
subject = "Software --- Software Engineering --- Design Tools and
Techniques (D.2.2): {\bf Structured programming**};
Software --- Software Engineering --- Software/Program
Verification (D.2.4): {\bf Correctness proofs};
Software --- Programming Languages --- Language
Constructs and Features (D.3.3): {\bf Control
structures}; Theory of Computation --- Logics and
Meanings of Programs --- Specifying and Verifying and
Reasoning about Programs (F.3.1): {\bf Assertions};
Theory of Computation --- Logics and Meanings of
Programs --- Specifying and Verifying and Reasoning
about Programs (F.3.1): {\bf Invariants}; Theory of
Computation --- Logics and Meanings of Programs ---
Specifying and Verifying and Reasoning about Programs
(F.3.1): {\bf Logics of programs}; Theory of
Computation --- Logics and Meanings of Programs ---
Specifying and Verifying and Reasoning about Programs
(F.3.1): {\bf Mechanical verification}; Theory of
Computation --- Logics and Meanings of Programs ---
Specifying and Verifying and Reasoning about Programs
(F.3.1): {\bf Pre- and post-conditions}; Theory of
Computation --- Logics and Meanings of Programs ---
Specifying and Verifying and Reasoning about Programs
(F.3.1): {\bf Specification techniques}; Theory of
Computation --- Logics and Meanings of Programs ---
Semantics of Programming Languages (F.3.2): {\bf
Algebraic approaches to semantics}; Theory of
Computation --- Logics and Meanings of Programs ---
Studies of Program Constructs (F.3.3): {\bf Control
primitives}; Computing Methodologies --- Symbolic and
Algebraic Manipulation --- Expressions and Their
Representation (I.1.1): {\bf Simplification of
expressions}; Computing Methodologies --- Symbolic and
Algebraic Manipulation --- Languages and Systems
(I.1.3): {\bf Special-purpose algebraic systems};
Computing Methodologies --- Artificial Intelligence ---
Automatic Programming (I.2.2): {\bf Program
modification}; Computing Methodologies --- Artificial
Intelligence --- Automatic Programming (I.2.2): {\bf
Program transformation}; Computing Methodologies ---
Artificial Intelligence --- Automatic Programming
(I.2.2): {\bf Program synthesis}; Computing
Methodologies --- Artificial Intelligence --- Automatic
Programming (I.2.2): {\bf Program verification}",
}
@Article{Gurevich:2000:SAS,
author = "Yuri Gurevich",
title = "Sequential abstract-state machines capture sequential
algorithms",
journal = j-TOCL,
volume = "1",
number = "1",
pages = "77--111",
month = jul,
year = "2000",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Oct 13 11:28:38 MDT 2000",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/citations/journals/tocl/2000-1-1/p77-gurevich/",
abstract = "We examine sequential algorithms and formulate a
sequential-time postulate, an abstract-state postulate,
and a bounded-exploration postulate. Analysis of the
postulates leads us to the notion of sequential
abstract-state machine and to the theorem in the title.
First we treat sequential algorithms that are
deterministic and noninteractive. Then we consider
sequential algorithms that may be nondeterministic and
that may interact with their environments.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "abstract-state machine; executable specification;
sequential algorithm; sequential ASM thesis;
specification; Turing's thesis",
subject = "Theory of Computation --- Computation by Abstract
Devices --- Models of Computation (F.1.1); Computing
Methodologies --- Simulation and Modeling --- Model
Development (I.6.5): {\bf Modeling methodologies}",
}
@Article{Grohe:2000:LOI,
author = "Martin Grohe and Thomas Schwentick",
title = "Locality of order-invariant first-order formulas",
journal = j-TOCL,
volume = "1",
number = "1",
pages = "112--130",
month = jul,
year = "2000",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Oct 13 11:28:38 MDT 2000",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/citations/journals/tocl/2000-1-1/p112-grohe/",
abstract = "A query is {\em local\/} if the decision of whether a
tuple in a structure satisfies this query only depends
on a small neighborhood of the tuple. We prove that all
queries expressible by {\em order-invariant\/}
first-order formulas are local.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "first-order logic; locality; logics; ordered
structures",
subject = "Theory of Computation --- Mathematical Logic and
Formal Languages --- Mathematical Logic (F.4.1)",
}
@Article{Liberatore:2000:CCR,
author = "Paolo Liberatore",
title = "Compilability and compact representations of revision
of {Horn} knowledge bases",
journal = j-TOCL,
volume = "1",
number = "1",
pages = "131--161",
month = jul,
year = "2000",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Oct 13 11:28:38 MDT 2000",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/citations/journals/tocl/2000-1-1/p131-liberatore/",
abstract = "Several methods have been proposed as an attempt to
deal with dynamically changing scenarios. From a
computational point of view, different formalisms have
different computational properties. In this article we
consider knowledge bases represented as sets of Horn
clauses. The importance of this case is twofold: first,
inference is polynomial, thus tractable; second, Horn
clauses represents causal relations between facts, thus
they are of great practical importance, although not
all propositional knowledge bases can be represented in
Horn form. The complexity of Horn revision is still
high, and in some cases coincides with the complexity
of the general (non-Horn) case. We analyze the
complexity of belief revision from the point of view of
the compilation [Cadoli et al. 1999]: we study the
possibility of reducing the complexity by allowing a
(possibly expensive) preprocessing of part of the input
of the problem. Extending the work of Cadoli et
al.[1996], we consider the problem of compact
representation of revision in the Horn case, i.e.,
given a knowledge base $T$ and an update $P$ (both
represented by Horn clauses) decide whether $T * P$,
the result of the revision, can be represented with a
propositional formula whose size is polynomial in the
size of $T$ and $P$. We give this representation for
all formalisms for which it exists, and we show that
the existence of a compact representation is related to
the possibility of decreasing the complexity of a
formalism via a preprocessing.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "compact representations; compilability",
subject = "Theory of Computation --- Computation by Abstract
Devices --- Complexity Measures and Classes (F.1.3):
{\bf Reducibility and completeness}; Computing
Methodologies --- Artificial Intelligence --- Deduction
and Theorem Proving (I.2.3): {\bf Nonmonotonic
reasoning and belief revision}; Computing Methodologies
--- Artificial Intelligence --- Knowledge
Representation Formalisms and Methods (I.2.4)",
}
@Article{Aziz:2000:MCC,
author = "Adnan Aziz and Kumud Sanwal and Vigyan Singhal and
Robert Brayton",
title = "Model-checking continuous-time {Markov} chains",
journal = j-TOCL,
volume = "1",
number = "1",
pages = "162--170",
month = jul,
year = "2000",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Oct 13 11:28:38 MDT 2000",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/citations/journals/tocl/2000-1-1/p162-aziz/",
abstract = "We present a logical formalism for expressing
properties of continuous-time Markov chains. The
semantics for such properties arise as a natural
extension of previous work on discrete-time Markov
chains to continuous time. The major result is that the
verification problem is decidable; this is shown using
results in algebraic and transcendental number
theory.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "formal verification; model checking; real time;
transcendental number theory",
subject = "Theory of Computation --- Logics and Meanings of
Programs --- Specifying and Verifying and Reasoning
about Programs (F.3.1): {\bf Logics of programs};
Computer Systems Organization ---
Computer-Communication Networks --- Network Protocols
(C.2.2): {\bf Protocol verification}; Mathematics of
Computing --- Numerical Analysis --- Roots of Nonlinear
Equations (G.1.5): {\bf Systems of equations};
Mathematics of Computing --- Probability and Statistics
(G.3): {\bf Stochastic processes}; Software ---
Software Engineering --- Software/Program Verification
(D.2.4): {\bf Model checking}",
}
@Article{Cohen:2000:NCP,
author = "Ernie Cohen and Dexter Kozen",
title = "A note on the complexity of propositional {Hoare}
logic",
journal = j-TOCL,
volume = "1",
number = "1",
pages = "171--174",
month = jul,
year = "2000",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Oct 13 11:28:38 MDT 2000",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/citations/journals/tocl/2000-1-1/p171-cohen/",
abstract = "We provide a simpler alternative proof of the {\em
PSPACE\/} -hardness of propositional Hoare logic
(PHL).",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Hoare logic; specification",
subject = "Software --- Software Engineering --- Design Tools and
Techniques (D.2.2): {\bf Structured programming**};
Software --- Software Engineering --- Software/Program
Verification (D.2.4): {\bf Correctness proofs};
Software --- Programming Languages --- Language
Constructs and Features (D.3.3): {\bf Control
structures}; Theory of Computation --- Logics and
Meanings of Programs --- Specifying and Verifying and
Reasoning about Programs (F.3.1): {\bf Assertions};
Theory of Computation --- Logics and Meanings of
Programs --- Specifying and Verifying and Reasoning
about Programs (F.3.1): {\bf Invariants}; Theory of
Computation --- Logics and Meanings of Programs ---
Specifying and Verifying and Reasoning about Programs
(F.3.1): {\bf Logics of programs}; Theory of
Computation --- Logics and Meanings of Programs ---
Specifying and Verifying and Reasoning about Programs
(F.3.1): {\bf Mechanical verification}; Theory of
Computation --- Logics and Meanings of Programs ---
Specifying and Verifying and Reasoning about Programs
(F.3.1): {\bf Pre- and post-conditions}; Theory of
Computation --- Logics and Meanings of Programs ---
Specifying and Verifying and Reasoning about Programs
(F.3.1): {\bf Specification techniques}; Theory of
Computation --- Logics and Meanings of Programs ---
Semantics of Programming Languages (F.3.2): {\bf
Algebraic approaches to semantics}; Theory of
Computation --- Logics and Meanings of Programs ---
Studies of Program Constructs (F.3.3): {\bf Control
primitives}; Computing Methodologies --- Artificial
Intelligence --- Automatic Programming (I.2.2): {\bf
Program verification}",
}
@Article{Friedman:2000:FOC,
author = "Nir Friedman and Joseph Y. Halpern and Daphne
Koller",
title = "First-order conditional logic for default reasoning
revisited",
journal = j-TOCL,
volume = "1",
number = "2",
pages = "175--207",
year = "2000",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 6 09:08:16 MST 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/citations/journals/tocl/2000-1-2/p175-friedman/",
abstract = "{\em Conditional logics\/} play an important role in
recent attempts to formulate theories of default
reasoning. This paper investigates first-order
conditional logic. We show that, as for first-order
probabilistic logic, it is important not to confound
{\em statistical\/} conditionals over the domain (such
as ``most birds fly''), and {\em subjective\/}
conditionals over possible worlds (such as ``I believe
that Tweety is unlikely to fly''). We then address the
issue of ascribing semantics to first-order conditional
logic. As in the propositional case, there are .many
possible semantics. To study the problem in a coherent
way, we use {\em plausibility structures}. These
provide us with a general framework in which many of
the standard approaches can be embedded. We show that
while these standard approaches are all the same at the
propositional level, they are significantly different
in the context of a first-order language. Furthermore,
we show that plausibilities provide the most natural
extension of conditional logic to the first-order
case:we provide a sound and complete axiomatization
that contains only the KLM properties and standard
axioms of first-order modal logic. We show that most of
the other approaches have additional properties, which
result in an inappropriate treatment of an infinitary
version of the {\em lottery paradox}.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
generalterms = "Theory",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "completeness; conditional logic; default reasoning;
first-order logic; KLM properties; plausibility
measures",
subject = "Theory of Computation --- Mathematical Logic and
Formal Languages --- Mathematical Logic (F.4.1): {\bf
Modal logic}; Computing Methodologies --- Artificial
Intelligence --- Deduction and Theorem Proving (I.2.3):
Nonmonotonic reasoning and belief revision; Computing
Methodologies --- Artificial Intelligence --- Knowledge
Representation Formalisms and Methods (I.2.4): {\bf
Modal logic}; Computing Methodologies --- Artificial
Intelligence --- Knowledge Representation Formalisms
and Methods (I.2.4): {\bf Predicate logic}",
}
@Article{Dix:2000:PAP,
author = "J{\"u}rgen Dix and Mirco Nanni and V. S.
Subrahmanian",
title = "Probabilistic agent programs",
journal = j-TOCL,
volume = "1",
number = "2",
pages = "208--246",
year = "2000",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 6 09:08:16 MST 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/citations/journals/tocl/2000-1-2/p208-dix/",
abstract = "Agents are small programs that autonomously take
actions based on changes in their environment or
``state''. Over the last few years, there has been an
increasing number of efforts to build agents that can
interact and/or collaborate with other agents. In one
of these efforts Eiter et al. [1999] have shown how
agents may be built on top of legacy code. However,
their framework assumes that agent states are
completely determined, and there is no uncertainty in
an agent's state. Thus, their framework allows an agent
developer to specify how his agents will react when the
agent is 100\% sure about what is true/false in the
world state. In this paper, we .propose the concept of
a {\em probabilistic agent program\/} and show how,
given an arbitrary program written in any imperative
language, we may build a declarative ``probabilistic''
agent program on top of it which supports decision
making in the presence of uncertainty. We provide two
alternative semantics for probabilistic programs. We
provide sound and complete algorithms to compute the
semantics of {\em positive\/} agent programs.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
generalterms = "Theory",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "logic programming; multi-agent reasoning;
probabilistic reasoning; uncertainty",
subject = "Computing Methodologies --- Artificial Intelligence
--- Distributed Artificial Intelligence (I.2.11): {\bf
Intelligent agents}; Computing Methodologies ---
Artificial Intelligence --- Deduction and Theorem
Proving (I.2.3): {\bf Uncertainty, ``fuzzy,'' and
probabilistic reasoning}; Computing Methodologies ---
Artificial Intelligence --- Knowledge Representation
Formalisms and Methods (I.2.4): {\bf Predicate logic};
Computing Methodologies --- Artificial Intelligence ---
Knowledge Representation Formalisms and Methods
(I.2.4): {\bf Modal logic}; Software --- Software
Engineering --- Interoperability (D.2.12); Information
Systems --- Database Management --- Systems (H.2.4);
Information Systems --- Database Management ---
Heterogeneous Databases (H.2.5)",
}
@Article{Lomuscio:2000:KMS,
author = "Alessio R. Lomuscio and Ron van der Meyden and Mark
Ryan",
title = "Knowledge in multiagent systems: initial
configurations and broadcast",
journal = j-TOCL,
volume = "1",
number = "2",
pages = "247--284",
year = "2000",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 6 09:08:16 MST 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/citations/journals/tocl/2000-1-2/p247-lomuscio/",
abstract = "The semantic framework for the modal logic of
knowledge due to Halpern and Moses provides a way to
ascribe knowledge to agents in distributed and
multiagent systems. In this paper we study two special
cases of this framework: {\em full systems\/} and {\em
hypercubes}. Both model static situations in which no
agents has any information about another agent's state.
Full systems and hypercubes are an appropriate model
for the initial configurations of many systems of
interest. We establish a correspondence between full
systems and hypercube systems and certain classes of
Kripke frames. We show that these classes of systems
correspond to the same logic. Moreover, this logic is
also the same as that generated by the larger class of
{\em weakly directed frames}. We provide a sound and
complete axiomatization, S5WD $n$ of this logic, and
study its computational complexity. Finally, we show
that under certain natural assumptions, in a model
where knowledge evolves over time, S5WD $n$
characteristics the properties of knowledge not just at
the initial configuration, but also at all later
configurations. In this particular, this holds for {\em
homogeneous broadcast systems,} which capture settings
in which agents are initially ignorant of each others
local states, operate synchronously, have perfect
recall, and can communicate only by broadcasting.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "completeness; computational complexity",
subject = "Theory of Computation --- Mathematical Logic and
Formal Languages --- Mathematical Logic (F.4.1): {\bf
Modal logic}; Computing Methodologies --- Artificial
Intelligence --- Knowledge Representation Formalisms
and Methods (I.2.4): {\bf Modal logic}; Computing
Methodologies --- Artificial Intelligence ---
Distributed Artificial Intelligence (I.2.11): {\bf
Multiagent systems}",
}
@Article{vanHentenryck:2000:SSO,
author = "Pascal van Hentenryck and Laurent Perron and
Jean-Fran{\c{c}}ois Puget",
title = "Search and strategies in {OPL}",
journal = j-TOCL,
volume = "1",
number = "2",
pages = "285--320",
year = "2000",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 6 09:08:16 MST 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/citations/journals/tocl/2000-1-2/p285-van_hentenryck/",
abstract = "OPL is a modeling language for mathematical
programming and combinatorial optimization. It is the
first language to combine high-level algebraic and set
notations from mathematical modeling languages with a
rich constraint language and the ability to specify
search procedures and strategies that are the essence
of constraint programming. This paper describes the
facilities available in OPL to specify search
procedures. It describes the abstractions of OPL to
specify both the search tree (search) and how to
explore it (strategies). The paper also illustrates how
to use these high-level constructs to implement
traditional search procedures in constraint programming
and scheduling.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "combinatorial optimization; constraint programming;
modeling languages; search",
subject = "Software --- Programming Languages (D.3); Software ---
Programming Languages --- Language Classifications
(D.3.2): {\bf Constraint and logic languages}; Software
--- Programming Languages --- Language Constructs and
Features (D.3.3): {\bf Constraints}; Software ---
Programming Languages --- Language Constructs and
Features (D.3.3): {\bf Control structures}",
}
@Article{Blass:2001:ICL,
author = "Andreas Blass and Yuri Gurevich",
title = "Inadequacy of computable loop invariants",
journal = j-TOCL,
volume = "2",
number = "1",
pages = "1--11",
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jul 25 07:10:50 MDT 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/articles/journals/tocl/2001-2-1/p1-blass/p1-blass.pdf;
http://www.acm.org/pubs/citations/journals/tocl/2001-2-1/p1-blass/",
abstract = "Hoare logic is a widely recommended verification tool.
There is, however, a problem of finding easily
checkable loop invariants; it is known that decidable
assertions do not suffice to verify while programs,
even when the pre- and postconditions are decidable. We
show here a stronger result: decidable invariants do
not suffice to verify single-loop programs. We also
show that this problem arises even in extremely simple
contexts. Let $N$ be the structure consisting of the
set of natural numbers together with the functions
$S(x) = x +1$, $D(x) = 2 (x) = *** x /2***$. There is a
single-loop program *** using only three variables $x,
y, z$ such that the asserted program $x = y = z = 0$
*** false is partially correct on $N$ but any loop
invariant $I(x,y,z)$ for this asserted program is
undecidable.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
generalterms = "Algorithms; Theory; Verification",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "assertion; automated deduction; automated reasoning;
Hoare logic; loop invariants; postcondition
uncomputable; precondition; recursive inseparability",
subject = "Theory of Computation --- Logics and Meanings of
Programs --- Specifying and Verifying and Reasoning
about Programs (F.3.1): {\bf Invariants}",
}
@Article{Fisher:2001:CTR,
author = "Michael Fisher and Clare Dixon and Martin Peim",
title = "Clausal temporal resolution",
journal = j-TOCL,
volume = "2",
number = "1",
pages = "12--56",
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jul 25 07:10:50 MDT 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/articles/journals/tocl/2001-2-1/p12-fisher/p12-fisher.pdf;
http://www.acm.org/pubs/citations/journals/tocl/2001-2-1/p12-fisher/",
abstract = "In this article, we examine how clausal resolution can
be applied to a specific, but widely used, nonclassical
logic, namely discrete linear temporal logic. Thus, we
first define a normal form for temporal formulae and
show how arbitrary temporal formulae can be translated
into the normal form, while preserving satisfiability.
We then introduce novel resolution rules that can be
applied to formulae in this normal form, provide a
range of examples, and examine the correctness and
complexity of this approach. Finally, we describe
related work and future developments concerning this
work.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
generalterms = "Algorithms; Theory; Verification",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "resolution; temporal logic; theorem proving",
subject = "Theory of Computation --- Mathematical Logic and
Formal Languages --- Mathematical Logic (F.4.1): {\bf
Temporal logic}; Computing Methodologies --- Artificial
Intelligence --- Deduction and Theorem Proving (I.2.3):
{\bf Resolution}",
}
@Article{Verbaeten:2001:TPL,
author = "Sofie Verbaeten and Danny {De Schreye} and
Konstantinos Sagonas",
title = "Termination proofs for logic programs with tabling",
journal = j-TOCL,
volume = "2",
number = "1",
pages = "57--92",
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jul 25 07:10:50 MDT 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/articles/journals/tocl/2001-2-1/p57-verbaeten/p57-verbaeten.pdf;
http://www.acm.org/pubs/citations/journals/tocl/2001-2-1/p57-verbaeten/",
abstract = "Tabled evaluation is receiving increasing attention in
the logic programming community. It avoids many of the
shortcomings of SLD execution and provides a more
flexible and often considerably more efficient
execution mechanism for logic programs. In particular,
tabled execution terminates more often than execution
based on SLD-resolution. In this article, we introduce
two notions of universal termination of logic
programming with tabling: quasi-termination and (the
stronger notion of) LG-termination. We present
sufficient conditions for these two notions of
termination, namely quasi-acceptability and
LG-acceptability, and we show that these conditions are
also necessary in case the selection of tabled
predicates meets certain natural criteria. Starting
from these conditions, we develop modular termination
proofs, i.e., proofs capable of combining termination
proofs of separate programs to obtain termination
proofs of combined programs. Finally, in the presence
of mode information, we state sufficient conditions
which form the basis for automatically proving
termination in a constraint-based way.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
generalterms = "Languages; Theory",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "prolog; SLG-resolution; tabling",
subject = "Software --- Programming Techniques --- Logic
Programming (D.1.6); Software --- Programming
Techniques --- Automatic Programming (D.1.2); Theory of
Computation --- Mathematical Logic and Formal Languages
--- Mathematical Logic (F.4.1): {\bf Logic and
constraint programming}",
}
@Article{Bryant:2001:PVU,
author = "Randal E. Bryant and Steven German and Miroslav N.
Velev",
title = "Processor verification using efficient reductions of
the logic of uninterpreted functions to propositional
logic",
journal = j-TOCL,
volume = "2",
number = "1",
pages = "93--134",
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jul 25 07:10:50 MDT 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/articles/journals/tocl/2001-2-1/p93-bryant/p93-bryant.pdf;
http://www.acm.org/pubs/citations/journals/tocl/2001-2-1/p93-bryant/",
abstract = "The logic of Equality with Uninterpreted Functions
(EUF) provides a means of abstracting the manipulation
of data by a processor when verifying the correctness
of its control logic. By reducing formulas in this
logic to propositional formulas, we can apply Boolean
methods such as ordered Binary Decision Diagrams (BDDs)
and Boolean satisfiability checkers to perform the
verification. We can exploit characteristics of the
formulas describing the verification conditions to
greatly simplify the propositional formulas generated.
We identify a class of terms we call ``p-terms'' for
which equality comparisons can only be used in
monotonically positive formulas. By applying suitable
abstractions to the hardware model, we can express the
functionality of data values and instruction addresses
flowing through an instruction pipeline with p-terms. A
decision procedure can exploit the restricted uses of
p-terms by considering only ``maximally diverse''
interpretations of the associated function symbols,
where every function application yields a different
value except when constrained by functional
consistency. We present two methods to translate
formulas in EUF into propositional logic. The first
interprets the formula over a domain of fixed-length
bit vectors and uses vectors of propositional variables
to encode domain variables. The second generates
formulas encoding the conditions under which pairs of
terms have equal valuations, introducing propositional
variables to encode the equality relations between
pairs of terms. Both of these approaches can exploit
maximal diversity to greatly reduce the number of
propositional variables that need to be introduced and
to reduce the overall formula sizes. We present
experimental results demonstrating the efficiency of
this approach when verifying pipelined processors using
the method proposed by Burch and Dill. Exploiting
positive equality allows us to overcome the
experimental blow-up experienced previously when
verifying microprocessors with load, store, and branch
instructions.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
generalterms = "Algorithms; Verification",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "decision procedures; processor verification;
uninterpreted functions",
subject = "Hardware --- Register-Transfer-Level Implementation
--- Design Aids (B.5.2): {\bf Verification}; Theory of
Computation --- Mathematical Logic and Formal Languages
--- Mathematical Logic (F.4.1): {\bf Mechanical theorem
proving}",
}
@Article{Libkin:2001:LCL,
author = "Leonid Libkin",
title = "Logics capturing local properties",
journal = j-TOCL,
volume = "2",
number = "1",
pages = "135--153",
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jul 25 07:10:50 MDT 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/articles/journals/tocl/2001-2-1/p135-libkin/p135-libkin.pdf;
http://www.acm.org/pubs/citations/journals/tocl/2001-2-1/p135-libkin/",
abstract = "Well-known theorems of Hanf and Gaifman establishing
locality of first-order definable properties have been
used in many applications. These theorems were recently
generalized to other logics, which led to new
applications in descriptive complexity and database
theory. However, a logical characterization of local
properties that correspond to Hanf's and Gaifman's
theorems is still lacking. Such a characterization only
exists for structures of bounded valence. In this
paper, we give logical characterizations of local
properties behind Hanf's and Gaifman's theorems. We
first deal with an infinitary logic with counting terms
and quantifiers that is known to capture Hanf-locality
on structures of bounded valence. We show that testing
isomorphism of neighborhoods can be added to it without
violating Hanf-locality, while increasing its
expressive power. We then show that adding local
second-order quantification to it captures precisely
all Hanf-local properties. To capture Gaifman-locality,
one must also add a (potentially infinite) case
statement. We further show that the hierarchy based on
the number of variants in the case statement is
strict.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
generalterms = "Languages; Theory",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "counting; locality; logic",
subject = "Theory of Computation --- Mathematical Logic and
Formal Languages --- Mathematical Logic (F.4.1)",
}
@Article{Rybina:2001:DPT,
author = "Tatiana Rybina and Andrei Voronkov",
title = "A decision procedure for term algebras with queues",
journal = j-TOCL,
volume = "2",
number = "2",
pages = "155--181",
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jul 25 07:10:50 MDT 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/articles/journals/tocl/2001-2-2/p155-rybina/p155-rybina.pdf;
http://www.acm.org/pubs/citations/journals/tocl/2001-2-2/p155-rybina/",
abstract = "In software verification it is often required to prove
statements about heterogeneous domains containing
elements of various sorts, such as counters, stacks,
lists, trees and queues. Any domain with counters,
stacks, lists, and trees (but not queues) can be easily
seen a special case of the term algebra, and hence a
decision procedure for term algebras can be applied to
decide the first-order theory of such a domain. We
present a quantifier-elimination procedure for the
first-order theory of term algebra extended with
queues. The complete axiomatization and decidability of
this theory can be immediately derived from the
procedure.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
generalterms = "Algorithms; Theory; Verification",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "queues; term algebras; trees; words",
subject = "Software --- Software Engineering --- Software/Program
Verification (D.2.4); Data --- Data Structures (E.1):
{\bf Lists, stacks, and queues}; Theory of Computation
--- Mathematical Logic and Formal Languages ---
Mathematical Logic (F.4.1): {\bf Computational logic};
Computing Methodologies --- Artificial Intelligence ---
Deduction and Theorem Proving (I.2.3): {\bf
Deduction}",
}
@Article{Voronkov:2001:HOP,
author = "Andrei Voronkov",
title = "How to optimize proof-search in modal logics: new
methods of proving redundancy criteria for sequent
calculi",
journal = j-TOCL,
volume = "2",
number = "2",
pages = "182--215",
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jul 25 07:10:50 MDT 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/articles/journals/tocl/2001-2-2/p182-voronkov/p182-voronkov.pdf;
http://www.acm.org/pubs/citations/journals/tocl/2001-2-2/p182-voronkov/",
abstract = "We present a bottom-up decision procedure for
propositional modal logic K based on the inverse
method. The procedure is based on the ``inverted''
version of a sequent calculus. To restrict the search
space, we prove a number of redundancy criteria for
derivations in the sequent calculus. We introduce {\em
a new technique\/} of proving redundancy criteria,
based on the analysis of tableau-based derivations in
K. Moreover, another new technique is based on
so-called {\em traces\/}. A new search with a strong
notion of subsumption. This technique is based on
so-called {\em traces\/}. A new formalization of the
inverse method in the form of a {\em path calculus\/}
considerably simplifies all proofs as compared to the
previously published presentations of the inverse
method. Experimental results demonstrate that our
method is competitive with many state-of-the-art
implementations of K.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
generalterms = "Experimentation; Theory",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "description logics; inverse method; modal logic;
proof-search; theorem proving",
subject = "Theory of Computation --- Mathematical Logic and
Formal Languages --- Mathematical Logic (F.4.1);
Computing Methodologies --- Artificial Intelligence ---
Knowledge Representation Formalisms and Methods
(I.2.4): {\bf Modal logic}",
}
@Article{Engelfriet:2001:MDS,
author = "Joost Engelfriet and Hendrik Jan Hoogeboom",
title = "{MSO} definable string transductions and two-way
finite-state transducers",
journal = j-TOCL,
volume = "2",
number = "2",
pages = "216--254",
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jul 25 07:10:50 MDT 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/articles/journals/tocl/2001-2-2/p216-engelfriet/p216-engelfriet.pdf;
http://www.acm.org/pubs/citations/journals/tocl/2001-2-2/p216-engelfriet/",
abstract = "We extend a classic result of B{\"u}chi, Elgot, and
Trakhtenbrot: MSO definable string transductions i.e.,
string-to-string functions that are definable by an
interpretation using monadic second-order (MSO) logic,
are exactly those realized by deterministic two-way
finite-state transducers, i.e., finite-state automata
with a two-way input tape and a one-way output tape.
Consequently, the equivalence of two mso definable
string transductions is decidable. In the
nondeterministic case however, MSO definable string
transductions, i.e., binary relations on strings that
are mso definable by an interpretation with parameters,
are incomparable to those realized by nondeterministic
two-way finite-state transducers. This is a motivation
to look for another machine model, and we show that
both classes of MSO definable string transductions are
characterized in terms of Hennie machines, i.e.,
two-way finite-state transducers that are allowed to
rewrite their input tape, but may visit each position
of their input only a bounded number of times.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
generalterms = "Theory",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "B{\"u} chi; Elgot; Hennie machine; interpretation;
monadic second-order logic; string transductions;
Trakhtenbrot; two-way finite-state transducers",
subject = "Theory of Computation --- Computation by Abstract
Devices --- Models of Computation (F.1.1): {\bf
Automata}; Theory of Computation --- Computation by
Abstract Devices --- Models of Computation (F.1.1):
{\bf Relations between models}; Theory of Computation
--- Mathematical Logic and Formal Languages ---
Mathematical Logic (F.4.1); Theory of Computation ---
Mathematical Logic and Formal Languages --- Formal
Languages (F.4.3)",
}
@Article{Antoniou:2001:RRD,
author = "Grigoris Antoniou and David Billington and Guido
Governatori and Michael J. Maher",
title = "Representation results for defeasible logic",
journal = j-TOCL,
volume = "2",
number = "2",
pages = "255--287",
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jul 25 07:10:50 MDT 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/articles/journals/tocl/2001-2-2/p255-antoniou/p255-antoniou.pdf;
http://www.acm.org/pubs/citations/journals/tocl/2001-2-2/p255-antoniou/",
abstract = "The importance of transformations and normal forms in
logic programming, and generally in computer science,
is well documented. This paper investigates
transformations and normal forms in the context of
Defeasible Logic, a simple but efficient formalism for
nonmonotonic reasoning based on rules and priorities.
The transformations described in this paper have two
main benefits: on one hand they can be used as a
theoretical tool that leads to a deeper understanding
of the formalism, and on the other hand they have been
used in the development of an efficient implementation
of defeasible logic.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
generalterms = "Theory",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "defeasible logic; normal forms; transformations",
subject = "Computing Methodologies --- Artificial Intelligence
--- Knowledge Representation Formalisms and Methods
(I.2.4); Theory of Computation --- Mathematical Logic
and Formal Languages --- Mathematical Logic (F.4.1):
{\bf Proof theory}",
}
@Article{Lukasiewicz:2001:PLP,
author = "Thomas Lukasiewicz",
title = "Probabilistic logic programming with conditional
constraints",
journal = j-TOCL,
volume = "2",
number = "3",
pages = "289--339",
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jul 25 07:10:50 MDT 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/citations/journals/tocl/2001-2-3/p289-lukasiewicz/",
abstract = "We introduce a new approach to probabilistic logic
programming in which probabilities are defined over a
set of possible worlds. More precisely, classical
program clauses are extended by a subinterval of [0,1]
that describes a range for the conditional probability
of the head of a clause given its body. We then analyze
the complexity of selected probabilistic logic
programming tasks. It turns out that probabilistic
logic programming is computationally more complex than
classical logic programming, More precisely, the
tractability of special cases of classical logic
programming generally does not carry over to the
corresponding special cases of probabilistic logic
programming. Moreover, we also draw a precise picture
of the complexity of deciding and computing tight
logical consequences in probabilistic reasoning with
conditional constraints in general. We then present
linear optimization techniques for deciding
satisfiability and computing tight logical consequences
of probabilistic logic programs. These techniques are
efficient in the special case in which we have little
relevant purely probabilistic knowledge. We finally
show that probabilistic logic programming under certain
syntactic and semantic restrictions is closely related
to van Emden's quantitative deduction, and thus has
computational properties similar to classical logic
programming. Based on this result, we present an
efficient approximation technique for probabilistic
logic programming.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
generalterms = "Algorithms; Languages; Theory",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "computational complexity; conditional constraint;
logic programming; many-valued logic; probabilistic
logic; probabilistic logic programming; probabilistic
reasoning; probability; quantitative deduction;
uncertainty",
subject = "Computing Methodologies --- Artificial Intelligence
--- Deduction and Theorem Proving (I.2.3): {\bf Logic
programming}; Computing Methodologies --- Artificial
Intelligence --- Deduction and Theorem Proving (I.2.3):
{\bf Uncertainty, ``fuzzy,'' and probabilistic
reasoning}; Computing Methodologies --- Artificial
Intelligence --- Knowledge Representation Formalisms
and Methods (I.2.4)",
}
@Article{Egly:2001:PCR,
author = "Uwe Egly and Hans Tompits",
title = "Proof-complexity results for nonmonotonic reasoning",
journal = j-TOCL,
volume = "2",
number = "3",
pages = "340--387",
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jul 25 07:10:50 MDT 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/citations/journals/tocl/2001-2-3/p340-egly/",
abstract = "It is well-known that almost all nonmonotonic
formalisms have a higher worst-case complexity than
classical reasoning. In some sense, this observation
denies one of the original motivations of nonmonotonic
systems, which was the expectation that nonmonotonic
rules should help to {\em speed-up\/} the reasoning
process, and not make it more difficult. In this paper,
we look at this issue from a proof-theoretical
perspective. We consider analytic calculi for certain
nonmonotonic logics and analyze to what extent the
presence of nonmonotonic rules can simplify the search
for proofs. In particular, we show that there are
classes of first-order formulae which have only
extremely long ``classical'' proofs, i.e., proofs
without applications of nonmonotonic rules, but there
are short proofs using nonmonotonic inferences.
Hence,despite the increase of complexity in the worst
case, there are instances where nonmonotonic reasoning
can be much simpler than classical (cut-free)
reasoning.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
generalterms = "Theory",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "circumscription; default logic; sequent calculi",
subject = "Computing Methodologies --- Artificial Intelligence
--- Deduction and Theorem Proving (I.2.3): {\bf
Nonmonotonic reasoning and belief revision}; Theory of
Computation --- Mathematical Logic and Formal Languages
--- Mathematical Logic (F.4.1): {\bf Computational
logic}; Theory of Computation --- Mathematical Logic
and Formal Languages --- Mathematical Logic (F.4.1):
{\bf Mechanical theorem proving}; Theory of Computation
--- Mathematical Logic and Formal Languages ---
Mathematical Logic (F.4.1): {\bf Proof theory}",
}
@Article{Alur:2001:PTL,
author = "Rajeev Alur and Kousha Etessami and Salvatore {La
Torre} and Doron Peled",
title = "Parametric temporal logic for ``model measuring''",
journal = j-TOCL,
volume = "2",
number = "3",
pages = "388--407",
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jul 25 07:10:50 MDT 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/citations/journals/tocl/2001-2-3/p388-alur/",
abstract = "We extend the standard model checking paradigm of
linear temporal logic, LTL, to a ``model measuring''
paradigm where one can obtain more quantitative
information beyond a ``Yes/No'' answer. For this
purpose, we define a {\em parametric temporal logic\/},
PLTL, which allows statements such as ``a request $p$
is followed in at most $x$ steps by a response $q$,''
where $x$ is a free variable. We show how one can,
given a formula ***( {\em x 1 ...,xk\/} ) of PLTL and a
system model {\em K\/} satisfies the property ***, but
if so find valuations which satisfy various optimality
criteria. In particular, we present algorithms for
finding valuations which minimize (or maximize) the
maximum (or minimum) of all parameters. Theses
algorithms exhibit the same PSPACE complexity as LTL
model checking. We show that our choice of syntax for
PLTL lies at the threshold of decidability for
parametric temporal logics, in that several natural
extensions have undecidable ``model measuring''
problems.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
generalterms = "Theory; Verification",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "model checking; quantitative analysis; temporal
logic",
subject = "Theory of Computation --- Mathematical Logic and
Formal Languages --- Mathematical Logic (F.4.1): {\bf
Temporal logic}; Software --- Software Engineering ---
Software/Program Verification (D.2.4): {\bf Model
checking}; Theory of Computation --- Logics and
Meanings of Programs --- Specifying and Verifying and
Reasoning about Programs (F.3.1): {\bf Logics of
programs}",
}
@Article{Kupferman:2001:WAA,
author = "Orna Kupferman and Moshe Y. Vardi",
title = "Weak alternating automata are not that weak",
journal = j-TOCL,
volume = "2",
number = "3",
pages = "408--429",
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jul 25 07:10:50 MDT 2001",
bibsource = "http://www.acm.org/pubs/toc/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
URL = "http://www.acm.org/pubs/citations/journals/tocl/2001-2-3/p408-kupferman/",
abstract = "Automata on infinite words are used for specification
and verification of nonterminating programs. Different
types of automata induce different levels of expressive
power, of succinctness, and of complexity. {\em
Alternating automata\/} have both existential and
universal branching modes and are particularly suitable
for specification of programs. In a {\em weak
alternating automata\/} the state space is partitioned
into partially ordered sets, and the automaton can
proceed from a certain set only to smaller sets.
Reasoning about weak alternating automata is easier
than reasoning about alternating automata with no
restricted structure. Known translations of alternating
automata to weak alternating automata involve
determinization, and therefore involve a
double-exponential blow-up. In this paper we describe a
quadratic translation, which circumvents the need for
determinization, of B{\"u}chi and co-B{\"u}chi
alternating automata to weak alternating automata.
Beyond the independent interest of such a translation,
it gives rise to a simple complementation algorithm for
nondeterministic B{\"u}chi automata.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
generalterms = "Theory; Verification",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "complementation; weak alternating automata",
subject = "Theory of Computation --- Computation by Abstract
Devices --- Models of Computation (F.1.1): {\bf
Automata}; Theory of Computation --- Computation by
Abstract Devices --- Modes of Computation (F.1.2): {\bf
Alternation and nondeterminism}; Theory of Computation
--- Logics and Meanings of Programs --- Specifying and
Verifying and Reasoning about Programs (F.3.1): {\bf
Mechanical verification}",
}
@Article{Apt:2001:E,
author = "Krzysztof R. Apt and Antonis C. Kakas and Fariba
Sadri",
title = "Editorial",
journal = j-TOCL,
volume = "2",
number = "4",
pages = "431--431",
month = oct,
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 19 15:32:34 MST 2002",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Reiter:2001:KBP,
author = "Ray Reiter",
title = "On knowledge-based programming with sensing in the
situation calculus",
journal = j-TOCL,
volume = "2",
number = "4",
pages = "433--457",
month = oct,
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 19 15:32:35 MST 2002",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Lavrac:2001:ETA,
author = "Nada Lavra{\v{c}} and Peter A. Flach",
title = "An extended transformation approach to inductive logic
programming",
journal = j-TOCL,
volume = "2",
number = "4",
pages = "458--494",
month = oct,
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 19 15:32:35 MST 2002",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{DeGiacomo:2001:IEG,
author = "Giuseppe {De Giacomo} and Hector J. Levesque and
Sebastian Sardi{\~n}a",
title = "Incremental execution of guarded theories",
journal = j-TOCL,
volume = "2",
number = "4",
pages = "495--525",
month = oct,
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 19 15:32:35 MST 2002",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Lifschitz:2001:SEL,
author = "Vladimir Lifschitz and David Pearce and Agust{\'\i}n
Valverde",
title = "Strongly equivalent logic programs",
journal = j-TOCL,
volume = "2",
number = "4",
pages = "526--541",
month = oct,
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 19 15:32:35 MST 2002",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Aiello:2001:VSP,
author = "Luigia Carlucci Aiello and Fabio Massacci",
title = "Verifying security protocols as planning in logic
programming",
journal = j-TOCL,
volume = "2",
number = "4",
pages = "542--580",
month = oct,
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 19 15:32:35 MST 2002",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Sergot:2001:CTN,
author = "Marek Sergot",
title = "A computational theory of normative positions",
journal = j-TOCL,
volume = "2",
number = "4",
pages = "581--622",
month = oct,
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 19 15:32:35 MST 2002",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Denecker:2001:LPR,
author = "Marc Denecker and Maurice Bruynooghe and Victor
Marek",
title = "Logic programming revisited: {Logic} programs as
inductive definitions",
journal = j-TOCL,
volume = "2",
number = "4",
pages = "623--654",
month = oct,
year = "2001",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 19 15:32:35 MST 2002",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Luttgen:2002:IBS,
author = "Gerald L{\"u}ttgen and Michael Mendler",
title = "The intuitionism behind {Statecharts} steps",
journal = j-TOCL,
volume = "3",
number = "1",
pages = "1--41",
month = jan,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 19 15:32:34 MST 2002",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Gottlob:2002:DLD,
author = "Georg Gottlob and Erich Gr{\"a}del and Helmut Veith",
title = "{Datalog LITE}: a deductive query language with linear
time model checking",
journal = j-TOCL,
volume = "3",
number = "1",
pages = "42--79",
month = jan,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 19 15:32:34 MST 2002",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{McDowell:2002:RHO,
author = "Raymond C. McDowell and Dale A. Miller",
title = "Reasoning with higher-order abstract syntax in a
logical framework",
journal = j-TOCL,
volume = "3",
number = "1",
pages = "80--136",
month = jan,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 19 15:32:34 MST 2002",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Asperti:2002:ILA,
author = "Andrea Asperti and Luca Roversi",
title = "Intuitionistic {Light Affine Logic}",
journal = j-TOCL,
volume = "3",
number = "1",
pages = "137--175",
month = jan,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Feb 19 15:32:34 MST 2002",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Donini:2002:DLM,
author = "Francesco M. Donini and Daniele Nardi and Riccardo
Rosati",
title = "Description logics of minimal knowledge and negation
as failure",
journal = j-TOCL,
volume = "3",
number = "2",
pages = "177--225",
month = apr,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:18 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bonatti:2002:SCP,
author = "Piero Andrea Bonatti and Nicola Olivetti",
title = "Sequent calculi for propositional nonmonotonic
logics",
journal = j-TOCL,
volume = "3",
number = "2",
pages = "226--278",
month = apr,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:18 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Tucker:2002:ACA,
author = "J. V. Tucker and J. I. Zucker",
title = "Abstract computability and algebraic specification",
journal = j-TOCL,
volume = "3",
number = "2",
pages = "279--333",
month = apr,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:18 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Abadi:2002:E,
author = "Mart{\'\i}n Abadi and Leonid Libkin and Frank
Pfenning",
title = "Editorial",
journal = j-TOCL,
volume = "3",
number = "3",
pages = "335--335",
month = jul,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:19 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Grohe:2002:FOT,
author = "Martin Grohe and Luc Segoufin",
title = "On first-order topological queries",
journal = j-TOCL,
volume = "3",
number = "3",
pages = "336--358",
month = jul,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:19 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Danos:2002:PGS,
author = "Vincent Danos and Russell S. Harmer",
title = "Probabilistic game semantics",
journal = j-TOCL,
volume = "3",
number = "3",
pages = "359--382",
month = jul,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:19 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Aehlig:2002:SAN,
author = "Klaus Aehlig and Helmut Schwichtenberg",
title = "A syntactical analysis of non-size-increasing
polynomial time computation",
journal = j-TOCL,
volume = "3",
number = "3",
pages = "383--401",
month = jul,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:19 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Buss:2002:RBC,
author = "Samuel R. Buss and Bruce M. Kapron",
title = "Resource-bounded continuity and sequentiality for
type-two functionals",
journal = j-TOCL,
volume = "3",
number = "3",
pages = "402--417",
month = jul,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:19 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Gradel:2002:BFB,
author = "Erich Gr{\"a}del and Colin Hirsch and Martin Otto",
title = "Back and forth between guarded and modal logics",
journal = j-TOCL,
volume = "3",
number = "3",
pages = "418--463",
month = jul,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:19 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bravetti:2002:DAW,
author = "Mario Bravetti and Roberto Gorrieri",
title = "Deciding and axiomatizing weak {ST} bisimulation for a
process algebra with recursion and action refinement",
journal = j-TOCL,
volume = "3",
number = "4",
pages = "465--520",
month = oct,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:19 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Givan:2002:PTC,
author = "Robert Givan and David Mcallester",
title = "Polynomial-time computation via local inference
relations",
journal = j-TOCL,
volume = "3",
number = "4",
pages = "521--541",
month = oct,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:19 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Kaminski:2002:RQA,
author = "Michael Kaminski and Guy Rey",
title = "Revisiting quantification in autoepistemic logic",
journal = j-TOCL,
volume = "3",
number = "4",
pages = "542--561",
month = oct,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:19 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bono:2002:TIE,
author = "Viviana Bono and Michele Bugliesi and Silvia Crafa",
title = "Typed interpretations of extensible objects",
journal = j-TOCL,
volume = "3",
number = "4",
pages = "562--603",
month = oct,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:19 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bryant:2002:BST,
author = "Randal E. Bryant and Miroslav N. Velev",
title = "{Boolean} satisfiability with transitivity
constraints",
journal = j-TOCL,
volume = "3",
number = "4",
pages = "604--627",
month = oct,
year = "2002",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:19 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Wadler:2003:MEM,
author = "Philip Wadler and Peter Thiemann",
title = "The marriage of effects and monads",
journal = j-TOCL,
volume = "4",
number = "1",
pages = "1--32",
month = jan,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:20 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Comon:2003:DCO,
author = "Hubert Comon and Paliath Narendran and Robert
Nieuwenhuis and Michael Rusinowitch",
title = "Deciding the confluence of ordered term rewrite
systems",
journal = j-TOCL,
volume = "4",
number = "1",
pages = "33--55",
month = jan,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:20 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Harland:2003:RDB,
author = "James Harland and David Pym",
title = "Resource-distribution via {Boolean} constraints",
journal = j-TOCL,
volume = "4",
number = "1",
pages = "56--90",
month = jan,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:20 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Lonc:2003:FPC,
author = "Zbigniew Lonc and Miroslaw Truszczy{\'n}ski",
title = "Fixed-parameter complexity of semantics for logic
programs",
journal = j-TOCL,
volume = "4",
number = "1",
pages = "91--119",
month = jan,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:20 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Dezani-Ciancaglini:2003:CCC,
author = "M. Dezani-Ciancaglini and F. Honsell and F. Alessi",
title = "A complete characterization of complete
intersection-type preorders",
journal = j-TOCL,
volume = "4",
number = "1",
pages = "120--147",
month = jan,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:20 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Angiulli:2003:CPM,
author = "Fabrizio Angiulli and Rachel Ben-Eliyahu-Zohary and
Giovambattista Ianni and Luigi Palopoli",
title = "Computational properties of metaquerying problems",
journal = j-TOCL,
volume = "4",
number = "2",
pages = "149--180",
month = apr,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:20 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bustan:2003:SBM,
author = "Doron Bustan and Orna Grumberg",
title = "Simulation-based minimization",
journal = j-TOCL,
volume = "4",
number = "2",
pages = "181--206",
month = apr,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:20 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Mesnard:2003:PLT,
author = "Fred Mesnard and Salvatore Ruggieri",
title = "On proving left termination of constraint logic
programs",
journal = j-TOCL,
volume = "4",
number = "2",
pages = "207--259",
month = apr,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:20 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Kutz:2003:LMS,
author = "Oliver Kutz and Frank Wolter and Holger Sturm and
Nobu-Yuki Suzuki and Michael Zakharyaschev",
title = "Logics of metric spaces",
journal = j-TOCL,
volume = "4",
number = "2",
pages = "260--294",
month = apr,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:20 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Gradel:2003:LSI,
author = "Erich Gr{\"a}del and Joseph Y. Halpern and Radha
Jaghadeesan and Adolfo Piperno",
title = "{LICS} 2001 special issue",
journal = j-TOCL,
volume = "4",
number = "3",
pages = "295--295",
month = jul,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:21 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Adler:2003:LBF,
author = "Micah Adler and Neil Immerman",
title = "An $n!$ lower bound on formula size",
journal = j-TOCL,
volume = "4",
number = "3",
pages = "296--314",
month = jul,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:21 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Alon:2003:TXV,
author = "Noga Alon and Tova Milo and Frank Neven and Dan Suciu
and Victor Vianu",
title = "Typechecking {XML} views of relational databases",
journal = j-TOCL,
volume = "4",
number = "3",
pages = "315--354",
month = jul,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:21 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Kozen:2003:SLP,
author = "Dexter Kozen and Jerzy Tiuryn",
title = "Substructural logic and partial correctness",
journal = j-TOCL,
volume = "4",
number = "3",
pages = "355--378",
month = jul,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:21 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Salibra:2003:TIO,
author = "Antonino Salibra",
title = "Topological incompleteness and order incompleteness of
the lambda calculus",
journal = j-TOCL,
volume = "4",
number = "3",
pages = "379--401",
month = jul,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:21 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Avigad:2003:EDS,
author = "Jeremy Avigad",
title = "Eliminating definitions and {Skolem} functions in
first-order logic",
journal = j-TOCL,
volume = "4",
number = "3",
pages = "402--415",
month = jul,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Aug 7 10:03:21 MDT 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Shen:2003:DAC,
author = "Yi-Dong Shen and Jia-Huai You and Li-Yan Yuan and
Samuel S. P. Shen and Qiang Yang",
title = "A dynamic approach to characterizing termination of
general logic programs",
journal = j-TOCL,
volume = "4",
number = "4",
pages = "417--430",
month = oct,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Oct 31 06:01:15 MST 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Libkin:2003:VIF,
author = "Leonid Libkin",
title = "Variable independence for first-order definable
constraints",
journal = j-TOCL,
volume = "4",
number = "4",
pages = "431--451",
month = oct,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Oct 31 06:01:15 MST 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bryans:2003:MCS,
author = "Jeremy Bryans and Howard Bowman and John Derrick",
title = "Model checking stochastic automata",
journal = j-TOCL,
volume = "4",
number = "4",
pages = "452--492",
month = oct,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Oct 31 06:01:15 MST 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Momigliano:2003:HOP,
author = "Alberto Momigliano and Frank Pfenning",
title = "Higher-order pattern complement and the strict
{$\lambda$}-calculus",
journal = j-TOCL,
volume = "4",
number = "4",
pages = "493--529",
month = oct,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Oct 31 06:01:15 MST 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Buneman:2003:IBP,
author = "Peter Buneman and Wenfei Fan and Scott Weinstein",
title = "Interaction between path and type constraints",
journal = j-TOCL,
volume = "4",
number = "4",
pages = "530--577",
month = oct,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Oct 31 06:01:15 MST 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Blass:2003:ASM,
author = "Andreas Blass and Yuri Gurevich",
title = "Abstract state machines capture parallel algorithms",
journal = j-TOCL,
volume = "4",
number = "4",
pages = "578--651",
month = oct,
year = "2003",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Oct 31 06:01:15 MST 2003",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Alur:2004:DGG,
author = "Rajeev Alur and Salvatore {La Torre}",
title = "Deterministic generators and games for {Ltl}
fragments",
journal = j-TOCL,
volume = "5",
number = "1",
pages = "1--25",
month = jan,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sun Jan 11 10:23:00 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bloom:2004:PFD,
author = "Bard Bloom and Wan Fokkink and Rob J. {Van
Glabbeek}",
title = "Precongruence formats for decorated trace semantics",
journal = j-TOCL,
volume = "5",
number = "1",
pages = "26--78",
month = jan,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sun Jan 11 10:23:00 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{DeNicola:2004:MLM,
author = "Rocco {De Nicola} and Michele Loreti",
title = "A modal logic for mobile agents",
journal = j-TOCL,
volume = "5",
number = "1",
pages = "79--128",
month = jan,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sun Jan 11 10:23:00 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Brass:2004:SLP,
author = "Stefan Brass and J{\"u}rgen Dix and Teodor C.
Przymusinski",
title = "Super logic programs",
journal = j-TOCL,
volume = "5",
number = "1",
pages = "129--176",
month = jan,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sun Jan 11 10:23:00 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Abdennadher:2004:AGR,
author = "Slim Abdennadher and Christophe Rigotti",
title = "Automatic generation of rule-based constraint solvers
over finite domains",
journal = j-TOCL,
volume = "5",
number = "2",
pages = "177--205",
month = apr,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:48 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Eiter:2004:LPA,
author = "Thomas Eiter and Wolfgang Faber and Nicola Leone and
Gerald Pfeifer and Axel Polleres",
title = "A logic programming approach to knowledge-state
planning: {Semantics} and complexity",
journal = j-TOCL,
volume = "5",
number = "2",
pages = "206--263",
month = apr,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:48 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Ratschan:2004:CAS,
author = "Stefan Ratschan",
title = "Convergent approximate solving of first-order
constraints by approximate quantifiers",
journal = j-TOCL,
volume = "5",
number = "2",
pages = "264--281",
month = apr,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:48 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Dawar:2004:IFP,
author = "Anuj Dawar and Erich Gr{\"a}del and Stephan
Kreutzer",
title = "Inflationary fixed points in modal logic",
journal = j-TOCL,
volume = "5",
number = "2",
pages = "282--315",
month = apr,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:48 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Subramani:2004:OLT,
author = "K. Subramani",
title = "Optimal length tree-like resolution refutations for
{2SAT} formulas",
journal = j-TOCL,
volume = "5",
number = "2",
pages = "316--320",
month = apr,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:48 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Godoy:2004:CTR,
author = "Guillem Godoy and Robert Nieuwenhuis and Ashish
Tiwari",
title = "Classes of term rewrite systems with polynomial
confluence problems",
journal = j-TOCL,
volume = "5",
number = "2",
pages = "321--331",
month = apr,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:48 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Ignjatovic:2004:SAL,
author = "Aleksandar Ignjatovic and Arun Sharma",
title = "Some applications of logic to feasibility in higher
types",
journal = j-TOCL,
volume = "5",
number = "2",
pages = "332--350",
month = apr,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:48 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Michel:2004:DBI,
author = "Laurent Michel and Pascal {Van Hentenryck}",
title = "A decomposition-based implementation of search
strategies",
journal = j-TOCL,
volume = "5",
number = "2",
pages = "351--383",
month = apr,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:48 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Mielniczuk:2004:BTF,
author = "Pawel Mielniczuk",
title = "Basic theory of feature trees",
journal = j-TOCL,
volume = "5",
number = "3",
pages = "385--402",
month = jul,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:49 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Neven:2004:FSM,
author = "Frank Neven and Thomas Schwentick and Victor Vianu",
title = "Finite state machines for strings over infinite
alphabets",
journal = j-TOCL,
volume = "5",
number = "3",
pages = "403--435",
month = jul,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:49 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bernardo:2004:SSR,
author = "Marco Bernardo",
title = "Symbolic semantic rules for producing compact {STGLAs}
from value passing process descriptions",
journal = j-TOCL,
volume = "5",
number = "3",
pages = "436--469",
month = jul,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:49 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bossi:2004:TSM,
author = "Annalisa Bossi and Sandro Etalle and Sabina Rossi and
Jan-Georg Smaus",
title = "Termination of simply moded logic programs with
dynamic scheduling",
journal = j-TOCL,
volume = "5",
number = "3",
pages = "470--507",
month = jul,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:49 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Loyer:2004:HBS,
author = "Yann Loyer and Nicolas Spyratos and Daniel Stamate",
title = "Hypothesis-based semantics of logic programs in
multivalued logics",
journal = j-TOCL,
volume = "5",
number = "3",
pages = "508--527",
month = jul,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:49 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Basin:2004:RMF,
author = "David Basin and Manuel Clavel and Jos{\'e} Meseguer",
title = "Reflective metalogical frameworks",
journal = j-TOCL,
volume = "5",
number = "3",
pages = "528--576",
month = jul,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:49 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Griffioen:2004:TNS,
author = "David Griffioen and Frits Vaandrager",
title = "A theory of normed simulations",
journal = j-TOCL,
volume = "5",
number = "4",
pages = "577--610",
month = oct,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:49 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Tucker:2004:AVC,
author = "J. V. Tucker and J. I. Zucker",
title = "Abstract versus concrete computation on metric partial
algebras",
journal = j-TOCL,
volume = "5",
number = "4",
pages = "611--668",
month = oct,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:49 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Lutz:2004:NTC,
author = "Carsten Lutz",
title = "{NEXP TIME}-complete description logics with concrete
domains",
journal = j-TOCL,
volume = "5",
number = "4",
pages = "669--705",
month = oct,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:49 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{DeBoer:2004:PCT,
author = "Frank S. {De Boer} and Maurizio Gabbrielli and Maria
Chiara Meo",
title = "Proving correctness of timed concurrent constraint
programs",
journal = j-TOCL,
volume = "5",
number = "4",
pages = "706--731",
month = oct,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:49 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Benhamou:2004:ICS,
author = "Fr{\'e}d{\'e}ric Benhamou and Fr{\'e}d{\'e}ric
Goualard and {\'E}ric Langu{\'e}nou and Marc Christie",
title = "Interval constraint solving for camera control and
motion planning",
journal = j-TOCL,
volume = "5",
number = "4",
pages = "732--767",
month = oct,
year = "2004",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Nov 4 07:59:49 MST 2004",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Henzinger:2005:CST,
author = "Thomas A. Henzinger and Rupak Majumdar and
Jean-Fran{\c{c}}ois Raskin",
title = "A classification of symbolic transition systems",
journal = j-TOCL,
volume = "6",
number = "1",
pages = "1--32",
month = jan,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Apr 12 06:59:19 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Giacobazzi:2005:MAD,
author = "Roberto Giacobazzi and Francesco Ranzato and Francesca
Scozzari",
title = "Making abstract domains condensing",
journal = j-TOCL,
volume = "6",
number = "1",
pages = "33--60",
month = jan,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Apr 12 06:59:19 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Harper:2005:ECF,
author = "Robert Harper and Frank Pfenning",
title = "On equivalence and canonical forms in the {LF} type
theory",
journal = j-TOCL,
volume = "6",
number = "1",
pages = "61--101",
month = jan,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Apr 12 06:59:19 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Verma:2005:NDT,
author = "Rakesh Verma and Ara Hayrapetyan",
title = "A new decidability technique for ground term rewriting
systems with applications",
journal = j-TOCL,
volume = "6",
number = "1",
pages = "102--123",
month = jan,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Apr 12 06:59:19 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Liau:2005:MLF,
author = "Churn-Jung Liau",
title = "A modal logic framework for multi-agent belief
fusion",
journal = j-TOCL,
volume = "6",
number = "1",
pages = "124--174",
month = jan,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Apr 12 06:59:19 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Hesselink:2005:EVP,
author = "Wim H. Hesselink",
title = "Eternity variables to prove simulation of
specifications",
journal = j-TOCL,
volume = "6",
number = "1",
pages = "175--201",
month = jan,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Apr 12 06:59:19 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Sakama:2005:IAS,
author = "Chiaki Sakama",
title = "Induction from answer sets in nonmonotonic logic
programs",
journal = j-TOCL,
volume = "6",
number = "2",
pages = "203--231",
month = apr,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Apr 12 06:59:19 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Cadoli:2005:CPN,
author = "Marco Cadoli and Thomas Eiter and Georg Gottlob",
title = "Complexity of propositional nested circumscription and
nested abnormality theories",
journal = j-TOCL,
volume = "6",
number = "2",
pages = "232--272",
month = apr,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Apr 12 06:59:19 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Kupferman:2005:LTB,
author = "Orna Kupferman and Moshe Y. Vardi",
title = "From linear time to branching time",
journal = j-TOCL,
volume = "6",
number = "2",
pages = "273--294",
month = apr,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Apr 12 06:59:19 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Wang:2005:CCW,
author = "Kewen Wang and Lizhu Zhou",
title = "Comparisons and computation of well-founded semantics
for disjunctive logic programs",
journal = j-TOCL,
volume = "6",
number = "2",
pages = "295--327",
month = apr,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Apr 12 06:59:19 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Cohen:2005:EAA,
author = "Sara Cohen and Yehoshua Sagiv and Werner Nutt",
title = "Equivalences among aggregate queries with negation",
journal = j-TOCL,
volume = "6",
number = "2",
pages = "328--360",
month = apr,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Apr 12 06:59:19 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Korovin:2005:KBC,
author = "Konstantin Korovin and Andrei Voronkov",
title = "{Knuth--Bendix} constraint solving is {NP}-complete",
journal = j-TOCL,
volume = "6",
number = "2",
pages = "361--388",
month = apr,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Apr 12 06:59:19 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Eiter:2005:RAE,
author = "Thomas Eiter and Michael Fink and Giuliana Sabbatini
and Hans Tompits",
title = "Reasoning about evolving nonmonotonic knowledge
bases",
journal = j-TOCL,
volume = "6",
number = "2",
pages = "389--440",
month = apr,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Apr 12 06:59:19 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Rondogiannis:2005:MMS,
author = "Panos Rondogiannis and William W. Wadge",
title = "Minimum model semantics for logic programs with
negation-as-failure",
journal = j-TOCL,
volume = "6",
number = "2",
pages = "441--467",
month = apr,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Apr 12 06:59:19 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Aehlig:2005:EFS,
author = "Klaus Aehlig and Jan Johannsen",
title = "An elementary fragment of second-order lambda
calculus",
journal = j-TOCL,
volume = "6",
number = "2",
pages = "468--480",
month = apr,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Apr 12 06:59:19 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Afrati:2005:DPT,
author = "Foto Afrati and Stavros Cosmadakis and Eug{\'e}nie
Foustoucos",
title = "{Datalog} programs and their persistency numbers",
journal = j-TOCL,
volume = "6",
number = "3",
pages = "481--518",
month = jul,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Jul 7 12:34:03 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Ferrari:2005:CDP,
author = "Mauro Ferrari and Camillo Fiorentini and Guido
Fiorino",
title = "On the complexity of the disjunction property in
intuitionistic and modal logics",
journal = j-TOCL,
volume = "6",
number = "3",
pages = "519--538",
month = jul,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Jul 7 12:34:03 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Stone:2005:DMG,
author = "Matthew Stone",
title = "Disjunction and modular goal-directed proof search",
journal = j-TOCL,
volume = "6",
number = "3",
pages = "539--577",
month = jul,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Jul 7 12:34:03 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Metcalfe:2005:SHC,
author = "George Metcalfe and Nicola Olivetti and Dov Gabbay",
title = "Sequent and hypersequent calculi for abelian and
{{\L}ukasiewicz} logics",
journal = j-TOCL,
volume = "6",
number = "3",
pages = "578--613",
month = jul,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Jul 7 12:34:03 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Boigelot:2005:EDP,
author = "Bernard Boigelot and S{\'e}bastien Jodogne and Pierre
Wolper",
title = "An effective decision procedure for linear arithmetic
over the integers and reals",
journal = j-TOCL,
volume = "6",
number = "3",
pages = "614--633",
month = jul,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Jul 7 12:34:03 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Schweikardt:2005:AFO,
author = "Nicole Schweikardt",
title = "Arithmetic, first-order logic, and counting
quantifiers",
journal = j-TOCL,
volume = "6",
number = "3",
pages = "634--671",
month = jul,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Jul 7 12:34:03 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Apt:2005:E,
author = "Krzysztof R. Apt",
title = "Editorial",
journal = j-TOCL,
volume = "6",
number = "4",
pages = "673--673",
month = oct,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Oct 17 07:03:25 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Kolaitis:2005:LSI,
author = "Phokion G. Kolaitis",
title = "{LICS 2003} special issue",
journal = j-TOCL,
volume = "6",
number = "4",
pages = "674--674",
month = oct,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Oct 17 07:03:25 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Khoussainov:2005:ALO,
author = "Bakhadyr Khoussainov and Sasha Rubin and Frank
Stephan",
title = "Automatic linear orders and trees",
journal = j-TOCL,
volume = "6",
number = "4",
pages = "675--700",
month = oct,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Oct 17 07:03:25 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Murawski:2005:AUP,
author = "Andrzej S. Murawski",
title = "About the undecidability of program equivalence in
finitary languages with state",
journal = j-TOCL,
volume = "6",
number = "4",
pages = "701--726",
month = oct,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Oct 17 07:03:25 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Lynch:2005:CLR,
author = "James F. Lynch",
title = "Convergence law for random graphs with specified
degree sequence",
journal = j-TOCL,
volume = "6",
number = "4",
pages = "727--748",
month = oct,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Oct 17 07:03:25 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Miller:2005:PTG,
author = "Dale Miller and Alwen Tiu",
title = "A proof theory for generic judgments",
journal = j-TOCL,
volume = "6",
number = "4",
pages = "749--783",
month = oct,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Oct 17 07:03:25 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Hughes:2005:PNU,
author = "Dominic J. D. Hughes and Rob J. {Van Glabbeek}",
title = "Proof nets for unit-free multiplicative-additive
linear logic",
journal = j-TOCL,
volume = "6",
number = "4",
pages = "784--842",
month = oct,
year = "2005",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Oct 17 07:03:25 MDT 2005",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Janhunen:2006:UPD,
author = "Tomi Janhunen and Ilkka Niemel{\"a} and Dietmar Seipel
and Patrik Simons and Jia-Huai You",
title = "Unfolding partiality and disjunctions in stable model
semantics",
journal = j-TOCL,
volume = "7",
number = "1",
pages = "1--37",
month = jan,
year = "2006",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Mar 9 05:54:01 MST 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{East:2006:PCB,
author = "Deborah East and Miroslaw Truszczy{\'n}ski",
title = "Predicate-calculus-based logics for modeling and
solving search problems",
journal = j-TOCL,
volume = "7",
number = "1",
pages = "38--83",
month = jan,
year = "2006",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Mar 9 05:54:01 MST 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Liberatore:2006:CRD,
author = "Paolo Liberatore",
title = "Complexity results on {DPLL} and resolution",
journal = j-TOCL,
volume = "7",
number = "1",
pages = "84--107",
month = jan,
year = "2006",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Mar 9 05:54:01 MST 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Degtyarev:2006:MTR,
author = "Anatoli Degtyarev and Michael Fisher and Boris
Konev",
title = "Monodic temporal resolution",
journal = j-TOCL,
volume = "7",
number = "1",
pages = "108--150",
month = jan,
year = "2006",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Mar 9 05:54:01 MST 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Dix:2006:HTP,
author = "J{\"u}rgen Dix and Sarit Kraus and V. S.
Subrahmanian",
title = "Heterogeneous temporal probabilistic agents",
journal = j-TOCL,
volume = "7",
number = "1",
pages = "151--198",
month = jan,
year = "2006",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Mar 9 05:54:01 MST 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Impagliazzo:2006:CDF,
author = "Russell Impagliazzo and Nathan Segerlind",
title = "Constant-depth {Frege} systems with counting axioms
polynomially simulate {Nullstellensatz} refutations",
journal = j-TOCL,
volume = "7",
number = "2",
pages = "199--218",
month = apr,
year = "2006",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu May 11 11:32:04 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Coppola:2006:OOR,
author = "Paolo Coppola and Simone Martini",
title = "Optimizing optimal reduction: a type inference
algorithm for elementary affine logic",
journal = j-TOCL,
volume = "7",
number = "2",
pages = "219--260",
month = apr,
year = "2006",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu May 11 11:32:04 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Lifschitz:2006:WTM,
author = "Vladimir Lifschitz and Alexander Razborov",
title = "Why are there so many loop formulas?",
journal = j-TOCL,
volume = "7",
number = "2",
pages = "261--268",
month = apr,
year = "2006",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu May 11 11:32:04 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Dovier:2006:DRS,
author = "Agostino Dovier and Andrea Formisano and Eugenio G.
Omodeo",
title = "Decidability results for sets with atoms",
journal = j-TOCL,
volume = "7",
number = "2",
pages = "269--301",
month = apr,
year = "2006",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu May 11 11:32:04 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Japaridze:2006:PCLa,
author = "Giorgi Japaridze",
title = "Propositional computability logic {I}",
journal = j-TOCL,
volume = "7",
number = "2",
pages = "302--330",
month = apr,
year = "2006",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu May 11 11:32:04 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Japaridze:2006:PCLb,
author = "Giorgi Japaridze",
title = "Propositional computability logic {II}",
journal = j-TOCL,
volume = "7",
number = "2",
pages = "331--362",
month = apr,
year = "2006",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu May 11 11:32:04 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Blass:2006:OIS,
author = "Andreas Blass and Yuri Gurevich",
title = "Ordinary interactive small-step algorithms, {I}",
journal = j-TOCL,
volume = "7",
number = "2",
pages = "363--419",
month = apr,
year = "2006",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu May 11 11:32:04 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Zhang:2006:LPB,
author = "Yan Zhang",
title = "Logic program-based updates",
journal = j-TOCL,
volume = "7",
number = "3",
pages = "421--472",
month = jul,
year = "2006",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1149114.1149115",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Oct 17 05:32:00 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Murawski:2006:FVM,
author = "Andrzej S. Murawski and C.-H. Luke Ong",
title = "Fast verification of {MLL} proof nets via {IMLL}",
journal = j-TOCL,
volume = "7",
number = "3",
pages = "473--498",
month = jul,
year = "2006",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1149114.1149116",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Oct 17 05:32:00 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Leone:2006:DSK,
author = "Nicola Leone and Gerald Pfeifer and Wolfgang Faber and
Thomas Eiter and Georg Gottlob and Simona Perri and
Francesco Scarcello",
title = "The {DLV} system for knowledge representation and
reasoning",
journal = j-TOCL,
volume = "7",
number = "3",
pages = "499--562",
month = jul,
year = "2006",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1149114.1149117",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Oct 17 05:32:00 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bistarelli:2006:SCC,
author = "Stefano Bistarelli and Ugo Montanari and Francesca
Rossi",
title = "Soft concurrent constraint programming",
journal = j-TOCL,
volume = "7",
number = "3",
pages = "563--589",
month = jul,
year = "2006",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1149114.1149118",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Oct 17 05:32:00 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Charlesworth:2006:CSC,
author = "Arthur Charlesworth",
title = "Comprehending software correctness implies
comprehending an intelligence-related limitation",
journal = j-TOCL,
volume = "7",
number = "3",
pages = "590--612",
month = jul,
year = "2006",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1149114.1149119",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Oct 17 05:32:00 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Son:2006:DDK,
author = "Tran Cao Son and Chitta Baral and Nam Tran and Sheila
Mcilraith",
title = "Domain-dependent knowledge in answer set planning",
journal = j-TOCL,
volume = "7",
number = "4",
pages = "613--657",
month = oct,
year = "2006",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1166109.1166110",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Oct 17 05:32:00 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Paulson:2006:DFE,
author = "Lawrence C. Paulson",
title = "Defining functions on equivalence classes",
journal = j-TOCL,
volume = "7",
number = "4",
pages = "658--675",
month = oct,
year = "2006",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1166109.1166111",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Oct 17 05:32:00 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Stone:2006:EES,
author = "Christopher A. Stone and Robert Harper",
title = "Extensional equivalence and singleton types",
journal = j-TOCL,
volume = "7",
number = "4",
pages = "676--722",
month = oct,
year = "2006",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1166109.1166112",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Oct 17 05:32:00 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Ratschan:2006:ESQ,
author = "Stefan Ratschan",
title = "Efficient solving of quantified inequality constraints
over the real numbers",
journal = j-TOCL,
volume = "7",
number = "4",
pages = "723--748",
month = oct,
year = "2006",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1166109.1166113",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Oct 17 05:32:00 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Cook:2006:SRW,
author = "Stephen Cook and Neil Thapen",
title = "The strength of replacement in weak arithmetic",
journal = j-TOCL,
volume = "7",
number = "4",
pages = "749--764",
month = oct,
year = "2006",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1166109.1166114",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Oct 17 05:32:00 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Vennekens:2006:SOA,
author = "Joost Vennekens and David Gilis and Marc Denecker",
title = "Splitting an operator: {Algebraic} modularity results
for logics with fixpoint semantics",
journal = j-TOCL,
volume = "7",
number = "4",
pages = "765--797",
month = oct,
year = "2006",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1166109.1166115",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Oct 17 05:32:00 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
note = "See erratum \cite{Vennekens:2007:ESO}.",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Desharnais:2006:KAD,
author = "Jules Desharnais and Bernhard M{\"o}ller and Georg
Struth",
title = "{Kleene} algebra with domain",
journal = j-TOCL,
volume = "7",
number = "4",
pages = "798--833",
month = oct,
year = "2006",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1166109.1166116",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Oct 17 05:32:00 MDT 2006",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bonacina:2007:ACI,
author = "Maria Paola Bonacina and Nachum Dershowitz",
title = "Abstract canonical inference",
journal = j-TOCL,
volume = "8",
number = "1",
pages = "??--??",
month = jan,
year = "2007",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sat Apr 14 09:26:09 MDT 2007",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "6",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Guglielmi:2007:SIS,
author = "Alessio Guglielmi",
title = "A system of interaction and structure",
journal = j-TOCL,
volume = "8",
number = "1",
pages = "??--??",
month = jan,
year = "2007",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sat Apr 14 09:26:09 MDT 2007",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "1",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Liberatore:2007:CPA,
author = "Paolo Liberatore and Marco Schaerf",
title = "Compilability of propositional abduction",
journal = j-TOCL,
volume = "8",
number = "1",
pages = "??--??",
month = jan,
year = "2007",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sat Apr 14 09:26:09 MDT 2007",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "2",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{McIver:2007:RQC,
author = "Annabelle McIver and Carroll Morgan",
title = "Results on the quantitative $\mu$-calculus $q{M}\mu$",
journal = j-TOCL,
volume = "8",
number = "1",
pages = "??--??",
month = jan,
year = "2007",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sat Apr 14 09:26:09 MDT 2007",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "3",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Rabinovich:2007:CL,
author = "Alexander Rabinovich",
title = "On compositionality and its limitations",
journal = j-TOCL,
volume = "8",
number = "1",
pages = "??--??",
month = jan,
year = "2007",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sat Apr 14 09:26:09 MDT 2007",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "4",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Vennekens:2007:ESO,
author = "Joost Vennekens and David Gilis and Marc Denecker",
title = "Erratum to splitting an operator: {Algebraic}
modularity results for logics with fixpoint semantics",
journal = j-TOCL,
volume = "8",
number = "1",
pages = "??--??",
month = jan,
year = "2007",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sat Apr 14 09:26:09 MDT 2007",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
note = "See \cite{Vennekens:2006:SOA}.",
acknowledgement = ack-nhfb,
articleno = "7",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Yorsh:2007:LCH,
author = "Greta Yorsh and Thomas Reps and Mooly Sagiv and
Reinhard Wilhelm",
title = "Logical characterizations of heap abstractions",
journal = j-TOCL,
volume = "8",
number = "1",
pages = "??--??",
month = jan,
year = "2007",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sat Apr 14 09:26:09 MDT 2007",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "5",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Benedikt:2007:LDQ,
author = "Michael Benedikt and Leonid Libkin and Frank Neven",
title = "Logical definability and query languages over ranked
and unranked trees",
journal = j-TOCL,
volume = "8",
number = "2",
pages = "??--??",
month = apr,
year = "2007",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sat Apr 14 09:26:10 MDT 2007",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "11",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Crary:2007:SCE,
author = "Karl Crary",
title = "Sound and complete elimination of singleton kinds",
journal = j-TOCL,
volume = "8",
number = "2",
pages = "??--??",
month = apr,
year = "2007",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sat Apr 14 09:26:10 MDT 2007",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "8",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Hitchcock:2007:ACD,
author = "John M. Hitchcock and Jack H. Lutz and Sebastiaan A.
Terwijn",
title = "The arithmetical complexity of dimension and
randomness",
journal = j-TOCL,
volume = "8",
number = "2",
pages = "??--??",
month = apr,
year = "2007",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sat Apr 14 09:26:10 MDT 2007",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "13",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Liberatore:2007:WFS,
author = "Paolo Liberatore",
title = "Where fail-safe default logics fail",
journal = j-TOCL,
volume = "8",
number = "2",
pages = "??--??",
month = apr,
year = "2007",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sat Apr 14 09:26:10 MDT 2007",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "10",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Lin:2007:RCA,
author = "Fangzhen Lin and Jia-Huai You",
title = "Recycling computed answers in rewrite systems for
abduction",
journal = j-TOCL,
volume = "8",
number = "2",
pages = "??--??",
month = apr,
year = "2007",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sat Apr 14 09:26:10 MDT 2007",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "9",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Sofronie-Stokkermans:2007:UBD,
author = "Viorica Sofronie-Stokkermans",
title = "On unification for bounded distributive lattices",
journal = j-TOCL,
volume = "8",
number = "2",
pages = "??--??",
month = apr,
year = "2007",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Sat Apr 14 09:26:10 MDT 2007",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "12",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Pedicini:2007:PPE,
author = "Marco Pedicini and Francesco Quaglia",
title = "{PELCR}: {Parallel} environment for optimal
lambda-calculus reduction",
journal = j-TOCL,
volume = "8",
number = "3",
pages = "14:1--14:??",
month = jul,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1243996.1243997",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:15 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In this article we present the implementation of an
environment supporting L{\'e}vy's optimal reduction for
the $\lambda$-calculus on parallel (or distributed)
computing systems. In a similar approach to Lamping's,
we base our work on a graph reduction technique, known
as directed virtual reduction, which is actually a
restriction of Danos-Regnier virtual reduction.\par
The environment, which we refer to as PELCR (parallel
environment for optimal lambda-calculus reduction),
relies on a strategy for directed virtual reduction,
namely half combustion. While developing PELCR we
adopted both a message aggregation technique, allowing
reduction of the communication overhead, and a fair
policy for distributing dynamically originated load
among processors.\par
We also present an experimental study demonstrating the
ability of PELCR to definitely exploit the parallelism
intrinsic to $\lambda$-terms while performing the
reduction. We show how PELCR allows achieving up to
70--80\% of the ideal speedup on last generation
multiprocessor computing systems. As a last note, the
software modules have been developed with the C
language and using a standard interface for message
passing, that is, MPI, thus making PELCR itself a
highly portable software package.",
acknowledgement = ack-nhfb,
articleno = "14",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "functional programming; geometry of interaction;
linear logic; optimal reduction; parallel
implementation; virtual reduction",
}
@Article{Blass:2007:OISa,
author = "Andreas Blass and Yuri Gurevich",
title = "Ordinary interactive small-step algorithms, {II}",
journal = j-TOCL,
volume = "8",
number = "3",
pages = "15:1--15:??",
month = jul,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1243996.1243998",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:15 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "This is the second in a series of three articles
extending the proof of the Abstract State Machine
Thesis---that arbitrary algorithms are behaviorally
equivalent to abstract state machines---to algorithms
that can interact with their environments during a
step, rather than only between steps. As in the first
article of the series, we are concerned here with
ordinary, small-step, interactive algorithms. This
means that the algorithms:\par
(1) proceed in discrete, global steps,\par
(2) perform only a bounded amount of work in each
step,\par
(3) use only such information from the environment as
can be regarded as answers to queries, and\par
(4) never complete a step until all queries from that
step have been answered.\par
After reviewing the previous article's formal
description of such algorithms and the definition of
behavioral equivalence, we define ordinary,
interactive, small-step abstract state machines (ASMs).
Except for very minor modifications, these are the
machines commonly used in the ASM literature. We define
their semantics in the framework of ordinary algorithms
and show that they satisfy the postulates for these
algorithms.\par
This material lays the groundwork for the final article
in the series, in which we shall prove the Abstract
State Machine thesis for ordinary, intractive,
small-step algorithms: All such algorithms are
equivalent to ASMs.",
acknowledgement = ack-nhfb,
articleno = "15",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "abstract state machines; equivalence of algorithms;
interaction; postulates; sequential algorithms",
}
@Article{Blass:2007:OISb,
author = "Andreas Blass and Yuri Gurevich",
title = "Ordinary interactive small-step algorithms, {III}",
journal = j-TOCL,
volume = "8",
number = "3",
pages = "16:1--16:??",
month = jul,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1243996.1243999",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:15 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "This is the third in a series of three articles
extending the proof of the Abstract State Machine
thesis---that arbitrary algorithms are behaviorally
equivalent to abstract state machines---to algorithms
that can interact with their environments during a
step, rather than only between steps. As in the first
two articles of the series, we are concerned here with
ordinary, small-step, interactive algorithms. This
means that the algorithms:\par
(1) proceed in discrete, global steps,\par
(2) perform only a bounded amount of work in each
step,\par
(3) use only such information from the environment as
can be regarded as answers to queries, and\par
(4) never complete a step until all queries from that
step have been answered.\par
After reviewing the previous articles' definitions of
such algorithms, of behavioral equivalence, and of
abstract state machines (ASMs), we prove the main
result: Every ordinary, interactive, small-step
algorithm is behaviorally equivalent to an ASM.\par
We also discuss some possible variations of and
additions to the ASM semantics.",
acknowledgement = ack-nhfb,
articleno = "16",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "abstract state machines; equivalence of algorithms;
interaction; postulates; sequential algorithms",
}
@Article{Eiter:2007:SCC,
author = "Thomas Eiter and Michael Fink and Stefan Woltran",
title = "Semantical characterizations and complexity of
equivalences in answer set programming",
journal = j-TOCL,
volume = "8",
number = "3",
pages = "17:1--17:??",
month = jul,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1243996.1244000",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:15 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In recent research on nonmonotonic logic programming,
repeatedly strong equivalence of logic programs $P$ and
$Q$ has been considered, which holds if the programs $P
\cup R$ and $Q \cup R$ have the same answer sets for
any other program $R$. This property strengthens the
equivalence of $P$ and $Q$ with respect to answer sets
(which is the particular case for $R = {\emptyset}$),
and has its applications in program optimization,
verification, and modular logic programming. In this
article, we consider more liberal notions of strong
equivalence, in which the actual form of $R$ may be
syntactically restricted. On the one hand, we consider
uniform equivalence where $R$ is a set of facts, rather
than a set of rules. This notion, which is well-known
in the area of deductive databases, is particularly
useful for assessing whether programs $P$ and $Q$ are
equivalent as components of a logic program which is
modularly structured. On the other hand, we consider
relativized notions of equivalence where $R$ ranges
over rules over a fixed alphabet, and thus generalize
our results to relativized notions of strong and
uniform equivalence. For all these notions, we consider
disjunctive logic programs in the propositional
(ground) case as well as some restricted classes,
providing semantical characterizations and analyzing
the computational complexity. Our results, which
naturally extend to answer set semantics for programs
with strong negation, complement the results on strong
equivalence of logic programs and pave the way for
optimizations in answer set solvers as a tool for
input-based problem solving.",
acknowledgement = ack-nhfb,
articleno = "17",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "answer set semantics; computational complexity;
program optimization; stable models; strong
equivalence; uniform equivalence",
}
@Article{Arieli:2007:PRP,
author = "Ofer Arieli",
title = "Paraconsistent reasoning and preferential entailments
by signed quantified {Boolean} formulae",
journal = j-TOCL,
volume = "8",
number = "3",
pages = "18:1--18:??",
month = jul,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1243996.1244001",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:15 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We introduce a uniform approach of representing a
variety of paraconsistent nonmonotonic formalisms by
quantified Boolean formulae (QBFs) in the context of
multiple-valued logics. We show that this framework
provides a useful platform for capturing, in a simple
and natural way, a wide range of methods for
preferential reasoning. The outcome is a subtle
approach to represent the underlying formalisms, which
induces a straightforward way to compute the
corresponding entailments: By incorporating
off-the-shelf QBF solvers it is possible to simulate
within our framework various kinds of preferential
formalisms, among which are Priest's logic LPm of
reasoning with minimal inconsistency, Batens' adaptive
logic ACLuNs2, Besnard and Schaub's inference relation
$|= n$, a variety of formula-preferential systems, some
bilattice-based preferential relations (e.g., $= I_1$
and $|= I_2$), and consequence relations for reasoning
with graded uncertainty, such as the four-valued logic
$|= 4 c$.",
acknowledgement = ack-nhfb,
articleno = "18",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "paraconsistent and nonmonotonic reasoning;
preferential semantics; quantified Boolean formulae",
}
@Article{Schmidt:2007:ATP,
author = "Renate A. Schmidt and Ullrich Hustadt",
title = "The axiomatic translation principle for modal logic",
journal = j-TOCL,
volume = "8",
number = "4",
pages = "19:1--19:??",
month = aug,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1276920.1276921",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:36 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In this paper we present a translation principle,
called the axiomatic translation, for reducing
propositional modal logics with background theories,
including triangular properties such as transitivity,
Euclideanness and functionality, to decidable fragments
of first-order logic. The goal of the axiomatic
translation principle is to find simplified theories,
which capture the inference problems in the original
theory, but in a way that can be readily automated and
is easier to deal with by existing (first-order)
theorem provers than the standard translation. The
principle of the axiomatic translation is conceptually
very simple and can be almost completely automated.
Soundness is automatic under reasonable assumptions,
general decidability results can be stated and
termination of ordered resolution is easily achieved.
The non-trivial part of the approach is proving
completeness. We prove results of completeness,
decidability, model generation, the small model
property and the interpolation property for a number of
common and less common modal logics. We also present
results of experiments with a number of first-order
logic theorem provers which are very encouraging.",
acknowledgement = ack-nhfb,
articleno = "19",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "completeness; decidability; small model property;
translation approach",
}
@Article{Laplante:2007:PAM,
author = "Sophie Laplante and Richard Lassaigne and
Fr{\'e}d{\'e}ric Magniez and Sylvain Peyronnet and
Michel de Rougemont",
title = "Probabilistic abstraction for model checking: an
approach based on property testing",
journal = j-TOCL,
volume = "8",
number = "4",
pages = "20:1--20:??",
month = aug,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1276920.1276922",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:36 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The goal of model checking is to verify the
correctness of a given program, on all its inputs. The
main obstacle, in many cases, is the intractably large
size of the program's transition system. Property
testing is a randomized method to verify whether some
fixed property holds on individual inputs, by looking
at a small random part of that input. We join the
strengths of both approaches by introducing a new
notion of probabilistic abstraction, and by extending
the framework of model checking to include the use of
these abstractions.\par
Our abstractions map transition systems associated with
large graphs to small transition systems associated
with small random subgraphs. This reduces the original
transition system to a family of small, even
constant-size, transition systems. We prove that with
high probability, ``sufficiently'' incorrect programs
will be rejected ($\varepsilon$-robustness). We also
prove that under a certain condition (exactness),
correct programs will never be rejected
(soundness).\par
Our work applies to programs for graph properties such
as bipartiteness, $k$-colorability, or any $\exists
\forall$ first order graph properties. Our main
contribution is to show how to apply the ideas of
property testing to syntactic programs for such
properties. We give a concrete example of an
abstraction for a program for bipartiteness. Finally,
we show that the relaxation of the test alone does not
yield transition systems small enough to use the
standard model checking method. More specifically, we
prove, using methods from communication complexity,
that the OBDD size remains exponential for approximate
bipartiteness.",
acknowledgement = ack-nhfb,
articleno = "20",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "approximate verification; model checking;
probabilistic abstraction; probabilistic verification;
property testing",
}
@Article{Durand:2007:FOQ,
author = "Arnaud Durand and Etienne Grandjean",
title = "First-order queries on structures of bounded degree
are computable with constant delay",
journal = j-TOCL,
volume = "8",
number = "4",
pages = "21:1--21:??",
month = aug,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1276920.1276923",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:36 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A relational structure is $d$-degree-bounded, for some
integer $d$, if each element of the domain belongs to
at most $d$ tuples. In this paper, we revisit the
complexity of the evaluation problem of not necessarily
Boolean first-order (FO) queries over
$d$-degree-bounded structures. Query evaluation is
considered here as a dynamical process. We prove that
any FO query on $d$-degree-bounded structures belongs
to the complexity class constant-Delay$_{\rm lin}$,
that is, can be computed by an algorithm that has two
separate parts: it has a precomputation step of time
linear in the size of the structure and then, it
outputs all solutions (i.e., tuples that satisfy the
formula) one by one with a constant delay (i.e.,
depending on the size of the formula only) between
each. Seen as a global process, this implies that
queries on $d$-degree-bounded structures can be
evaluated in total time $f(|\varphi|).(|S| +
|\varphi(S)|)$ and space $g(|\varphi|).|S|$ where $S$
is the structure, $\varphi$ is the formula,
$\varphi(S)$ is the result of the query and $f$, $g$
are some fixed functions.
Among other things, our results generalize a result of
Seese on the data complexity of the model-checking
problem for $d$-degree-bounded structures. Besides, the
originality of our approach compared to related results
is that it does not rely on the Hanf's model-theoretic
technique and is simple and informative since it
essentially rests on a quantifier elimination method.",
acknowledgement = ack-nhfb,
articleno = "21",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "computational complexity; enumeration problems;
first-order logic",
}
@Article{Olivetti:2007:SCT,
author = "Nicola Olivetti and Gian Luca Pozzato and Camilla B.
Schwind",
title = "A sequent calculus and a theorem prover for standard
conditional logics",
journal = j-TOCL,
volume = "8",
number = "4",
pages = "22:1--22:??",
month = aug,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1276920.1276924",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:36 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In this paper we present a cut-free sequent calculus,
called SeqS, for some standard conditional logics. The
calculus uses labels and transition formulas and can be
used to prove decidability and space complexity bounds
for the respective logics. We also show that these
calculi can be the base for uniform proof systems.
Moreover, we present CondLean, a theorem prover in
Prolog for these calculi.",
acknowledgement = ack-nhfb,
articleno = "22",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "analytic sequent calculi; automated deduction;
conditional logics; labeled deductive systems; logic
programming; proof theory",
}
@Article{Choi:2007:RPR,
author = "C. W. Choi and J. H. M. Lee and P. J. Stuckey",
title = "Removing propagation redundant constraints in
redundant modeling",
journal = j-TOCL,
volume = "8",
number = "4",
pages = "23:1--23:??",
month = aug,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1276920.1276925",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:36 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A widely adopted approach to solving constraint
satisfaction problems combines systematic tree search
with various degrees of constraint propagation for
pruning the search space. One common technique to
improve the execution efficiency is to add redundant
constraints, which are constraints logically implied by
others in the problem model. However, some redundant
constraints are propagation redundant and hence do not
contribute additional propagation information to the
constraint solver. Redundant constraints arise
naturally in the process of redundant modeling where
two models of the same problem are connected and
combined through channeling constraints. In this paper,
we give general theorems for proving propagation
redundancy of one constraint with respect to channeling
constraints and constraints in the other model. We
illustrate, on problems from CSPlib
(http://www.csplib.org), how detecting and removing
propagation redundant constraints in redundant modeling
can speed up search by several order of magnitudes.",
acknowledgement = ack-nhfb,
articleno = "23",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "constraint propagation; redundant constraints;
redundant modeling",
}
@Article{Hung:2007:PIX,
author = "Edward Hung and Lise Getoor and V. S. Subrahmanian",
title = "Probabilistic interval {XML}",
journal = j-TOCL,
volume = "8",
number = "4",
pages = "24:1--24:??",
month = aug,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1276920.1276926",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:36 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Interest in XML databases has been expanding rapidly
over the last few years. In this paper, we study the
problem of incorporating probabilistic information into
XML databases. We propose the Probabilistic Interval
XML ( PIXML for short) data model in this paper. Using
this data model, users can express probabilistic
information within XML markups. In addition, we provide
two alternative formal model-theoretic semantics for
PIXML data. The first semantics is a ``global''
semantics which is relatively intuitive, but is not
directly amenable to computation. The second semantics
is a ``local'' semantics which supports efficient
computation. We prove several correspondence results
between the two semantics. To our knowledge, this is
the first formal model theoretic semantics for
probabilistic interval XML. We then provide an
operational semantics that may be used to compute
answers to queries and that is correct for a large
class of probabilistic instances.",
acknowledgement = ack-nhfb,
articleno = "24",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "semistructured databases; XML",
}
@Article{Shoham:2007:GBF,
author = "Sharon Shoham and Orna Grumberg",
title = "A game-based framework for {CTL} counterexamples and
3-valued abstraction-refinement",
journal = j-TOCL,
volume = "9",
number = "1",
pages = "1:1--1:??",
month = dec,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1297658.1297659",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:49 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "This work exploits and extends the game-based
framework of CTL model checking for counterexample and
incremental abstraction-refinement. We define a
game-based CTL model checking for abstract models over
the 3-valued semantics, which can be used for
verification as well as refutation. The model checking
process of an abstract model may end with an indefinite
result, in which case we suggest a new notion of
refinement, which eliminates indefinite results of the
model checking. This provides an iterative
abstraction-refinement framework. This framework is
enhanced by an incremental algorithm, where refinement
is applied only where indefinite results exist and
definite results from prior iterations are used within
the model checking algorithm. We also define the notion
of annotated counterexamples, which are sufficient and
minimal counterexamples for full CTL. We present an
algorithm that uses the game board of the model
checking game to derive an annotated counterexample in
case the examined system model refutes the checked
formula.",
acknowledgement = ack-nhfb,
articleno = "1",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "3-valued semantics; abstraction-refinement;
counterexamples; CTL; model checking games; temporal
logic",
}
@Article{Avigad:2007:FVP,
author = "Jeremy Avigad and Kevin Donnelly and David Gray and
Paul Raff",
title = "A formally verified proof of the prime number
theorem",
journal = j-TOCL,
volume = "9",
number = "1",
pages = "2:1--2:23",
month = dec,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1297658.1297660",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:49 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The prime number theorem, established by Hadamard and
de la Vall{\'e}e Poussin independently in 1896, asserts
that the density of primes in the positive integers is
asymptotic to $1/\ln x$. Whereas their proofs made
serious use of the methods of complex analysis,
elementary proofs were provided by Selberg and
Erd{\H{o}}s in 1948. We describe a formally verified
version of Selberg's proof, obtained using the Isabelle
proof assistant.",
acknowledgement = ack-nhfb,
articleno = "2",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "formal verification; prime number theorem",
}
@Article{VandenBussche:2007:PTI,
author = "Jan {Van den Bussche} and Stijn Vansummeren",
title = "Polymorphic type inference for the named nested
relational calculus",
journal = j-TOCL,
volume = "9",
number = "1",
pages = "3:1--3:??",
month = dec,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1297658.1297661",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:49 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The named nested relational calculus is the canonical
query language for the complex object database model
and is equipped with a natural static type system.
Given an expression in the language, without type
declarations for the input variables, there is the
problem of whether there are any input type
declarations under which the expression is well-typed.
Moreover, if there are, then which are they, and what
is the corresponding output type for each of these?
This problem is solved by a logic-based approach, and
the decision problem is shown to be NP-complete.",
acknowledgement = ack-nhfb,
articleno = "3",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "complexity; named nested relational calculus;
typability; type inference",
}
@Article{Lahiri:2007:PAI,
author = "Shuvendu K. Lahiri and Randal E. Bryant",
title = "Predicate abstraction with indexed predicates",
journal = j-TOCL,
volume = "9",
number = "1",
pages = "4:1--4:??",
month = dec,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1297658.1297662",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:49 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Predicate abstraction provides a powerful tool for
verifying properties of infinite-state systems using a
combination of a decision procedure for a subset of
first-order logic and symbolic methods originally
developed for finite-state model checking. We consider
models containing first-order state variables, where
the system state includes mutable functions and
predicates. Such a model can describe systems
containing arbitrarily large memories, buffers, and
arrays of identical processes. We describe a form of
predicate abstraction that constructs a formula over a
set of universally quantified variables to describe
invariant properties of the first-order state
variables. We provide a formal justification of the
soundness of our approach and describe how it has been
used to verify several hardware and software designs,
including a directory-based cache coherence protocol.",
acknowledgement = ack-nhfb,
articleno = "4",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "abstract interpretation; cache-coherence protocols;
formal verification; infinite-state verification;
invariant synthesis; predicate abstraction",
}
@Article{Baier:2007:VNP,
author = "Christel Baier and Nathalie Bertrand and Philippe
Schnoebelen",
title = "Verifying nondeterministic probabilistic channel
systems against $\omega$-regular linear-time
properties",
journal = j-TOCL,
volume = "9",
number = "1",
pages = "5:1--5:??",
month = dec,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1297658.1297663",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:49 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Lossy channel systems (LCS's) are systems of finite
state processes that communicate via unreliable
unbounded fifo channels. We introduce NPLCS's, a
variant of LCS's where message losses have a
probabilistic behavior while the component processes
behave nondeterministically, and study the decidability
of qualitative verification problems for
$\omega$-regular linear-time properties.\par
We show that---in contrast to finite-state Markov
decision processes---the satisfaction relation for
linear-time formulas depends on the type of schedulers
that resolve the nondeterminism. While the qualitative
model checking problem for the full class of
history-dependent schedulers is undecidable, the same
question for finite-memory schedulers can be solved
algorithmically. Additionally, some special kinds of
reachability, or recurrent reachability, qualitative
properties yield decidable verification problems for
the full class of schedulers, which---for this
restricted class of problems---are as powerful as
finite-memory schedulers, or even a subclass of them.",
acknowledgement = ack-nhfb,
articleno = "5",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "communication protocols; lossy channels; Markov
decision processes; probabilistic models",
}
@Article{Biernacka:2007:CFE,
author = "Ma{\l}gorzata Biernacka and Olivier Danvy",
title = "A concrete framework for environment machines",
journal = j-TOCL,
volume = "9",
number = "1",
pages = "6:1--6:??",
month = dec,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1297658.1297664",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:49 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We materialize the common understanding that calculi
with explicit substitutions provide an intermediate
step between an abstract specification of substitution
in the lambda-calculus and its concrete
implementations. To this end, we go back to Curien's
original calculus of closures (an early calculus with
explicit substitutions), we extend it minimally so that
it can also express one-step reduction strategies, and
we methodically derive a series of environment machines
from the specification of two one-step reduction
strategies for the lambda-calculus: normal order and
applicative order. The derivation extends Danvy and
Nielsen's refocusing-based construction of abstract
machines with two new steps: one for coalescing two
successive transitions into one, and the other for
unfolding a closure into a term and an environment in
the resulting abstract machine. The resulting
environment machines include both the Krivine machine
and the original version of Krivine's machine,
Felleisen et al.'s CEK machine, and Leroy's Zinc
abstract machine.",
acknowledgement = ack-nhfb,
articleno = "6",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "abstract machines; closures; derivation; explicit
substitutions",
}
@Article{Angiulli:2007:ODL,
author = "Fabrizio Angiulli and Gianluigi Greco and Luigi
Palopoli",
title = "Outlier detection by logic programming",
journal = j-TOCL,
volume = "9",
number = "1",
pages = "7:1--7:??",
month = dec,
year = "2007",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1297658.1297665",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:28:49 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The development of effective knowledge discovery
techniques has become a very active research area in
recent years due to the important impact it has had in
several relevant application domains. One interesting
task therein is that of singling out anomalous
individuals from a given population, for example, to
detect rare events in time-series analysis settings, or
to identify objects whose behavior is deviant w.r.t. a
codified standard set of rules. Such exceptional
individuals are usually referred to as outliers in the
literature.\par
In this article, the concept of outlier is formally
stated in the context of knowledge-based systems, by
generalizing that originally proposed in Angiulli et
al. [2003] in the context of default theories. The
chosen formal framework here is that of logic
programming, wherein potential applications of
techniques for outlier detection are thoroughly
discussed. The proposed formalization is a novel one
and helps to shed light on the nature of outliers
occurring in logic bases. Also the exploitation of
minimality criteria in outlier detection is
illustrated.\par
The computational complexity of outlier detection
problems arising in this novel setting is also
thoroughly investigated and accounted for in the paper.
Finally, rewriting algorithms are proposed that
transform any outlier detection problem into an
equivalent inference problem under stable model
semantics, thereby making outlier computation effective
and realizable on top of any stable model solver.",
acknowledgement = ack-nhfb,
articleno = "7",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "computational complexity; logic programming;
nonmonotonic reasoning; outlier detection",
}
@Article{Ghilardi:2008:CCF,
author = "Silvio Ghilardi and Enrica Nicolini and Daniele
Zucchelli",
title = "A comprehensive combination framework",
journal = j-TOCL,
volume = "9",
number = "2",
pages = "8:1--8:??",
month = mar,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1342991.1342992",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:03 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We define a general notion of a fragment within
higher-order type theory; a procedure for constraint
satisfiability in combined fragments is outlined,
following Nelson-Oppen schema. The procedure is in
general only sound, but it becomes terminating and
complete when the shared fragment enjoys suitable
noetherianity conditions and admits an abstract version
of a ``Keisler-Shelah-like'' isomorphism theorem. We
show that this general decidability transfer result
covers recent work on combination in first-order
theories as well as in various intensional logics such
as description, modal, and temporal logics.",
acknowledgement = ack-nhfb,
articleno = "8",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "combination; decision procedures; higher-order logic;
modal and description logics; satisfiability modulo
theory",
}
@Article{Sakama:2008:CAS,
author = "Chiaki Sakama and Katsumi Inoue",
title = "Coordination in answer set programming",
journal = j-TOCL,
volume = "9",
number = "2",
pages = "9:1--9:??",
month = mar,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1342991.1342993",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:03 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "This article studies a semantics of multiple logic
programs, and synthesizes a program having such a
collective semantics. More precisely, the following two
problems are considered: given two logic programs $P_1$
and $P_2$, which have the collections of answer sets
${\rm AS}(P_1)$ and ${\rm AS}(P_2)$, respectively; (i)
find a program $Q$ which has the set of answer sets
such that ${\rm AS}(Q) = {\rm AS}(P_1) \cup {\rm
AS}(P_2)$; (ii) find a program R which has the set of
answer sets such that ${\rm AS}(R) = {AS}(P_1) \cap
{AS}(P_2)$. A program $Q$ satisfying the condition (i)
is called generous coordination of $P_1$ and $P_2$; and
$R$ satisfying (ii) is called rigorous coordination of
$P_1$ and $P_2$. Generous coordination retains all of
the answer sets of each program, but permits the
introduction of additional answer sets of the other
program. By contrast, rigorous coordination forces each
program to give up some answer sets, but the result
remains within the original answer sets for each
program. Coordination provides a program that reflects
the meaning of two or more programs. We provide methods
for constructing these two types of coordination and
address its application to logic-based multi-agent
systems.",
acknowledgement = ack-nhfb,
articleno = "9",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "answer set programming; coordination; multiagent
systems",
}
@Article{Lasota:2008:ATA,
author = "Slawomir Lasota and Igor Walukiewicz",
title = "Alternating timed automata",
journal = j-TOCL,
volume = "9",
number = "2",
pages = "10:1--10:??",
month = mar,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1342991.1342994",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:03 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A notion of alternating timed automata is proposed. It
is shown that such automata with only one clock have
decidable emptiness problem over finite words. This
gives a new class of timed languages that is closed
under boolean operations and which has an effective
presentation. We prove that the complexity of the
emptiness problem for alternating timed automata with
one clock is nonprimitive recursive. The proof gives
also the same lower bound for the universality problem
for nondeterministic timed automata with one clock. We
investigate extension of the model with
epsilon-transitions and prove that emptiness is
undecidable. Over infinite words, we show
undecidability of the universality problem.",
acknowledgement = ack-nhfb,
articleno = "10",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "alternation; emptyness problem; timed automata",
}
@Article{Klaedtke:2008:BAS,
author = "Felix Klaedtke",
title = "Bounds on the automata size for {Presburger}
arithmetic",
journal = j-TOCL,
volume = "9",
number = "2",
pages = "11:1--11:??",
month = mar,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1342991.1342995",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:03 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Automata provide a decision procedure for Presburger
arithmetic. However, until now only crude lower and
upper bounds were known on the sizes of the automata
produced by the automata-based approach for Presburger
arithmetic. In this article, we give an upper bound on
the number of states of the minimal deterministic
automaton for a Presburger arithmetic formula. This
bound depends on the length of the formula and the
quantifiers occurring in it. We establish the upper
bound by comparing the automata for Presburger
arithmetic formulas with the formulas produced by a
quantifier-elimination method. We show that our bound
is tight, also for nondeterministic automata. Moreover,
we provide automata constructions for atomic formulas
and establish lower bounds for the automata for linear
equations and inequations.",
acknowledgement = ack-nhfb,
articleno = "11",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "automata-based decision procedures; complexity;
Presburger arithmetic; quantifier elimination",
}
@Article{Bruyere:2008:DPM,
author = "V{\'e}ronique Bruy{\`e}re and Emmanuel Dall'olio and
Jean-Fran{\c{c}}ois Raskin",
title = "Durations and parametric model-checking in timed
automata",
journal = j-TOCL,
volume = "9",
number = "2",
pages = "12:1--12:??",
month = mar,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1342991.1342996",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:03 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We consider the problem of model-checking a parametric
extension of the logic TCTL over timed automata and
establish its decidability. Given a timed automaton, we
show that the set of durations of runs starting from a
region and ending in another region is definable in
Presburger arithmetic (when the time domain is
discrete) or in a real arithmetic (when the time domain
is dense). Using this logical definition, we show that
the parametric model-checking problem for the logic
TCTL can be solved algorithmically; the proof of this
result is simple. More generally, we are able to
effectively characterize the values of the parameters
that satisfy the parametric TCTL formula with respect
to the given timed automaton.",
acknowledgement = ack-nhfb,
articleno = "12",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "model-checking; Presburger arithmetic; timed
automata",
}
@Article{Geerts:2008:FOC,
author = "Floris Geerts and Sofie Haesevoets and Bart
Kuijpers",
title = "First-order complete and computationally complete
query languages for spatio-temporal databases",
journal = j-TOCL,
volume = "9",
number = "2",
pages = "13:1--13:??",
month = mar,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1342991.1342997",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:03 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We address a fundamental question concerning
spatio-temporal database systems: ``What are exactly
spatio-temporal queries?'' We define spatio-temporal
queries to be computable mappings that are also
generic, meaning that the result of a query may only
depend to a limited extent on the actual internal
representation of the spatio-temporal data. Genericity
is defined as invariance under groups of geometric
transformations that preserve certain characteristics
of spatio-temporal data (e.g., collinearity, distance,
velocity, acceleration, {\ldots}). These groups depend
on the notions that are relevant in particular
spatio-temporal database applications. These
transformations also have the distinctive property that
they respect the monotone and unidirectional nature of
time.\par
We investigate different genericity classes with
respect to the constraint database model for
spatio-temporal databases and we identify sound and
complete languages for the first-order and the
computable queries in these genericity classes. We
distinguish between genericity determined by
time-invariant transformations, genericity notions
concerning physical quantities and genericity
determined by time-dependent transformations.",
acknowledgement = ack-nhfb,
articleno = "13",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "constraint databases; moving objects; query languages;
spatial databases; spatio-temporal databases",
}
@Article{Denecker:2008:LNI,
author = "Marc Denecker and Eugenia Ternovska",
title = "A logic of nonmonotone inductive definitions",
journal = j-TOCL,
volume = "9",
number = "2",
pages = "14:1--14:??",
month = mar,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1342991.1342998",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:03 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Well-known principles of induction include monotone
induction and different sorts of nonmonotone induction
such as inflationary induction, induction over
well-founded sets and iterated induction. In this work,
we define a logic formalizing induction over
well-founded sets and monotone and iterated induction.
Just as the principle of positive induction has been
formalized in FO(LFP), and the principle of
inflationary induction has been formalized in FO(IFP),
this article formalizes the principle of iterated
induction in a new logic for Nonmonotone Inductive
Definitions (ID-logic). The semantics of the logic is
strongly influenced by the well-founded semantics of
logic programming.\par
This article discusses the formalisation of different
forms of (non-)monotone induction by the well-founded
semantics and illustrates the use of the logic for
formalizing mathematical and common-sense knowledge. To
model different types of induction found in
mathematics, we define several subclasses of
definitions, and show that they are correctly
formalized by the well-founded semantics. We also
present translations into classical first or second
order logic. We develop modularity and totality results
and demonstrate their use to analyze and simplify
complex definitions. We illustrate the use of the logic
for temporal reasoning. The logic formally extends
Logic Programming, Abductive Logic Programming and
Datalog, and thus formalizes the view on these
formalisms as logics of (generalized) inductive
definitions.",
acknowledgement = ack-nhfb,
articleno = "14",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "classical logic; inductive definitions; logic
programming",
}
@Article{Dovier:2008:UAC,
author = "Agostino Dovier and Carla Piazza and Gianfranco
Rossi",
title = "A uniform approach to constraint-solving for lists,
multisets, compact lists, and sets",
journal = j-TOCL,
volume = "9",
number = "3",
pages = "15:1--15:??",
month = jun,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1352582.1352583",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:17 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Lists, multisets, and sets are well-known data
structures whose usefulness is widely recognized in
various areas of computer science. They have been
analyzed from an axiomatic point of view with a
parametric approach in Dovier et al. [1998], where the
relevant unification algorithms have been developed. In
this article, we extend these results considering more
general constraints, namely, equality and membership
constraints and their negative counterparts.",
acknowledgement = ack-nhfb,
articleno = "15",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "compact lists; lists; membership and equality
constraints; multisets; sets",
}
@Article{Crary:2008:FCC,
author = "Karl Crary and Susmit Sarkar",
title = "Foundational certified code in the {Twelf} metalogical
framework",
journal = j-TOCL,
volume = "9",
number = "3",
pages = "16:1--16:??",
month = jun,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1352582.1352584",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:17 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Foundational certified code systems seek to prove
untrusted programs to be safe relative to safety
policies given in terms of actual machine
architectures, thereby improving the systems'
flexibility and extensibility. Using the Twelf
metalogical framework, we have constructed a safety
policy for the IA-32 architecture with a trusted
runtime library. The safety policy is based on a
formalized operational semantics. We have also
developed a complete, foundational proof that a fully
expressive typed assembly language satisfies that
safety policy.",
acknowledgement = ack-nhfb,
articleno = "16",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "foundational certified code; logic programming;
metalogic",
}
@Article{Genaim:2008:INS,
author = "Samir Genaim and Andy King",
title = "Inferring non-suspension conditions for logic programs
with dynamic scheduling",
journal = j-TOCL,
volume = "9",
number = "3",
pages = "17:1--17:??",
month = jun,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1352582.1352585",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:17 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A logic program consists of a logic component and a
control component. The former is a specification in
predicate logic whereas the latter defines the order of
subgoal selection. The order of subgoal selection is
often controlled with delay declarations that specify
that a subgoal is to suspend until some condition on
its arguments is satisfied. Reasoning about delay
declarations is notoriously difficult for the
programmer and it is not unusual for a program and a
goal to reduce to a state that contains a subgoal that
suspends indefinitely. Suspending subgoals are usually
unintended and often indicate an error in the logic or
the control. A number of abstract interpretation
schemes have therefore been proposed for checking that
a given program and goal cannot reduce to such a state.
This article considers a reversal of this problem,
advocating an analysis that for a given program infers
a class of goals that do not lead to suspension. This
article shows that this more general approach can have
computational, implementational and user-interface
advantages. In terms of user-interface, this approach
leads to a lightweight point-and-click mode of
operation in which, after directing the analyser at a
file, the user merely has to inspect the results
inferred by the analysis. In terms of implementation,
the analysis can be straightforwardly realized as two
simple fixpoint computations. In terms of computation,
by modeling $n!$ different schedulings of $n$ subgoals
with a single Boolean function, it is possible to
reason about the suspension behavior of large programs.
In particular, the analysis is fast enough to be
applied repeatedly within the program development
cycle. The article also demonstrates that the method is
precise enough to locate bugs in existing programs.",
acknowledgement = ack-nhfb,
articleno = "17",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "abstract interpretation; concurrency; debugging; logic
programming",
}
@Article{Blass:2008:PTW,
author = "Andreas Blass and Yuri Gurevich",
title = "Program termination and well partial orderings",
journal = j-TOCL,
volume = "9",
number = "3",
pages = "18:1--18:??",
month = jun,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1352582.1352586",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:17 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The following known observation is useful in
establishing program termination: if a transitive
relation $R$ is covered by finitely many well-founded
relations $U_1, \ldots, U_n$ then $R$ is well-founded.
A question arises how to bound the ordinal height $|R|$
of the relation $R$ in terms of the ordinals $\alpha_i
= |U_i|$. We introduce the notion of the stature
$||P||$ of a well partial ordering $P$ and show that
$|R| \leq ||\alpha_1 \times \cdots \times \alpha_n||$
and that this bound is tight. The notion of stature is
of considerable independent interest. We define $||P||$
as the ordinal height of the forest of nonempty bad
sequences of $P$, but it has many other natural and
equivalent definitions. In particular, $||P||$ is the
supremum, and in fact the maximum, of the lengths of
linearizations of $P$. And $||\alpha_1 \times \cdots
\times \alpha_n ||$ is equal to the natural product
$\alpha_1 \otimes \ldots \otimes \alpha_n$.",
acknowledgement = ack-nhfb,
articleno = "18",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "covering observation; game criterion; program
termination; well partial orderings",
}
@Article{Blass:2008:ASM,
author = "Andreas Blass and Yuri Gurevich",
title = "Abstract state machines capture parallel algorithms:
{Correction} and extension",
journal = j-TOCL,
volume = "9",
number = "3",
pages = "19:1--19:??",
month = jun,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1352582.1352587",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:17 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We consider parallel algorithms working in sequential
global time, for example, circuits or parallel random
access machines (PRAMs). Parallel abstract state
machines (parallel ASMs) are such parallel algorithms,
and the parallel ASM thesis asserts that every parallel
algorithm is behaviorally equivalent to a parallel ASM.
In an earlier article, we axiomatized parallel
algorithms, proved the ASM thesis, and proved that
every parallel ASM satisfies the axioms. It turned out
that we were too timid in formulating the axioms; they
did not allow a parallel algorithm to create components
on the fly. This restriction did not hinder us from
proving that the usual parallel models, like circuits
or PRAMs or even alternating Turing machines, satisfy
the postulates. But it resulted in an error in our
attempt to prove that parallel ASMs always satisfy the
postulates. To correct the error, we liberalize our
axioms and allow on-the-fly creation of new parallel
components. We believe that the improved axioms
accurately express what parallel algorithms ought to
be. We prove the parallel thesis for the new, corrected
notion of parallel algorithms, and we check that
parallel ASMs satisfy the new axioms.",
acknowledgement = ack-nhfb,
articleno = "19",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "abstract state machine; ASM thesis; parallel
algorithm; parallel programming; postulates for
parallel computation",
}
@Article{Chockler:2008:WCS,
author = "Hana Chockler and Joseph Y. Halpern and Orna
Kupferman",
title = "What causes a system to satisfy a specification?",
journal = j-TOCL,
volume = "9",
number = "3",
pages = "20:1--20:??",
month = jun,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1352582.1352588",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:17 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
note = "See erratum \cite{Chockler:2010:EWC}.",
abstract = "Even when a system is proven to be correct with
respect to a specification, there is still a question
of how complete the specification is, and whether it
really covers all the behaviors of the system. Coverage
metrics attempt to check which parts of a system are
actually relevant for the verification process to
succeed. Recent work on coverage in model checking
suggests several coverage metrics and algorithms for
finding parts of the system that are not covered by the
specification. The work has already proven to be
effective in practice, detecting design errors that
escape early verification efforts in industrial
settings. In this article, we relate a formal
definition of causality given by Halpern and Pearl to
coverage. We show that it gives significant insight
into unresolved issues regarding the definition of
coverage and leads to potentially useful extensions of
coverage. In particular, we introduce the notion of
responsibility, which assigns to components of a system
a quantitative measure of their relevance to the
satisfaction of the specification.",
acknowledgement = ack-nhfb,
articleno = "20",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "causality; coverage metrics; model checking;
responsibility",
}
@Article{Bova:2008:PSH,
author = "Simone Bova and Franco Montagna",
title = "Proof search in {H{\'a}jek}'s basic logic",
journal = j-TOCL,
volume = "9",
number = "3",
pages = "21:1--21:??",
month = jun,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1352582.1352589",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:17 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We introduce a proof system for H{\'a}jek's logic BL
based on a relational hypersequents framework. We prove
that the rules of our logical calculus, called RHBL,
are sound and invertible with respect to any valuation
of BL into a suitable algebra, called $(\omega)[0,1]$.
Refining the notion of reduction tree that arises
naturally from RHBL, we obtain a decision algorithm for
BL provability whose running time upper bound is
$2^O(n)$, where $n$ is the number of connectives of the
input formula. Moreover, if a formula is unprovable, we
exploit the constructiveness of a polynomial time
algorithm for leaves validity for providing a procedure
to build countermodels in $(\omega)[0, 1]$. Finally,
since the size of the reduction tree branches is
$O(n^3)$, we can describe a polynomial time
verification algorithm for BL unprovability.",
acknowledgement = ack-nhfb,
articleno = "21",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "automated deduction; countermodel building; fuzzy
logic",
}
@Article{Calvanese:2008:CQC,
author = "Diego Calvanese and Giuseppe {De Giacomo} and Maurizio
Lenzerini",
title = "Conjunctive query containment and answering under
description logic constraints",
journal = j-TOCL,
volume = "9",
number = "3",
pages = "22:1--22:??",
month = jun,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1352582.1352590",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:17 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Query containment and query answering are two
important computational tasks in databases. While query
answering amounts to computing the result of a query
over a database, query containment is the problem of
checking whether, for every database, the result of one
query is a subset of the result of another
query.\par
In this article, we deal with unions of conjunctive
queries, and we address query containment and query
answering under description logic constraints. Every
such constraint is essentially an inclusion dependency
between concepts and relations, and their expressive
power is due to the possibility of using complex
expressions in the specification of the dependencies,
for example, intersection and difference of relations,
special forms of quantification, regular expressions
over binary relations. These types of constraints
capture a great variety of data models, including the
relational, the entity-relationship, and the
object-oriented model, all extended with various forms
of constraints. They also capture the basic features of
the ontology languages used in the context of the
Semantic Web.\par
We present the following results on both query
containment and query answering. We provide a method
for query containment under description logic
constraints, thus showing that the problem is
decidable, and analyze its computational complexity. We
prove that query containment is undecidable in the case
where we allow inequalities in the right-hand-side
query, even for very simple constraints and queries. We
show that query answering under description logic
constraints can be reduced to query containment, and
illustrate how such a reduction provides upper-bound
results with respect to both combined and data
complexity.",
acknowledgement = ack-nhfb,
articleno = "22",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "computational compexity; conjunctive queries;
description logics; query containment",
}
@Article{Nanevski:2008:CMT,
author = "Aleksandar Nanevski and Frank Pfenning and Brigitte
Pientka",
title = "Contextual modal type theory",
journal = j-TOCL,
volume = "9",
number = "3",
pages = "23:1--23:??",
month = jun,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1352582.1352591",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jun 16 14:29:17 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The intuitionistic modal logic of necessity is based
on the judgmental notion of categorical truth. In this
article we investigate the consequences of relativizing
these concepts to explicitly specified contexts. We
obtain contextual modal logic and its type-theoretic
analogue. Contextual modal type theory provides an
elegant, uniform foundation for understanding
metavariables and explicit substitutions. We sketch
some applications in functional programming and logical
frameworks.",
acknowledgement = ack-nhfb,
articleno = "23",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "intuitionistic modal logic; logical frameworks; type
theory",
}
@Article{Chevalier:2008:CRS,
author = "Yannick Chevalier and Ralf K{\"u}sters and Micha{\"e}l
Rusinowitch and Mathieu Turuani",
title = "Complexity results for security protocols with
{Diffie--Hellman} exponentiation and commuting public
key encryption",
journal = j-TOCL,
volume = "9",
number = "4",
pages = "24:1--24:??",
month = aug,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1380572.1380573",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Aug 29 14:02:20 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We show that the insecurity problem for protocols with
modular exponentiation and arbitrary products allowed
in exponents is NP-complete. This result is based on a
protocol and intruder model which is powerful enough to
uncover known attacks on the Authenticated Group
Diffie--Hellman (A-GDH.2) protocol suite. To prove our
results, we develop a general framework in which the
Dolev--Yao intruder is extended by generic intruder
rules. This framework is also applied to obtain
complexity results for protocols with commuting public
key encryption.",
acknowledgement = ack-nhfb,
articleno = "24",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "algebraic properties; complexity; Diffie--Hellman
exponentiation; Dolev--Yao model; protocols",
}
@Article{Wolter:2008:UUA,
author = "Frank Wolter and Michael Zakharyaschev",
title = "Undecidability of the unification and admissibility
problems for modal and description logics",
journal = j-TOCL,
volume = "9",
number = "4",
pages = "25:1--25:??",
month = aug,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1380572.1380574",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Aug 29 14:02:20 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We show that the unification problem ``is there a
substitution instance of a given formula that is
provable in a given logic?'' is undecidable for basic
modal logics K and K4 extended with the universal
modality. It follows that the admissibility problem for
inference rules is undecidable for these logics as
well. These are the first examples of standard
decidable modal logics for which the unification and
admissibility problems are undecidable. We also prove
undecidability of the unification and admissibility
problems for K and K4 with at least two modal operators
and nominals (instead of the universal modality),
thereby showing that these problems are undecidable for
basic hybrid logics. Recently, unification has been
introduced as an important reasoning service for
description logics. The undecidability proof for K with
nominals can be used to show the undecidability of
unification for Boolean description logics with
nominals (such as ALCO and SHIQO). The undecidability
proof for K with the universal modality can be used to
show that the unification problem relative to role
boxes is undecidable for Boolean description logics
with transitive roles, inverse roles, and role
hierarchies (such as SHI and SHIQ).",
acknowledgement = ack-nhfb,
articleno = "25",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "admissible rule; decidability; description logic;
hybrid logic; unification",
}
@Article{Heymans:2008:OAS,
author = "Stijn Heymans and Davy {Van Nieuwenborgh} and Dirk
Vermeir",
title = "Open answer set programming with guarded programs",
journal = j-TOCL,
volume = "9",
number = "4",
pages = "26:1--26:??",
month = aug,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1380572.1380575",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Aug 29 14:02:20 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Open answer set programming (OASP) is an extension of
answer set programming where one may ground a program
with an arbitrary superset of the program's constants.
We define a fixed-point logic (FPL) extension of
Clark's completion such that open answer sets
correspond to models of FPL formulas and identify a
syntactic subclass of programs, called ({\em
loosely\/}) {\em guarded programs}. Whereas reasoning
with general programs in OASP is undecidable, the FPL
translation of (loosely) guarded programs falls in the
decidable (loosely) guarded fixed-point logic
($\mu$(L)GF). Moreover, we reduce normal closed ASP to
loosely guarded OASP, enabling, for the first time, a
characterization of an answer set semantics by $\mu$LGF
formulas.\par
We further extend the open answer set semantics for
programs with generalized literals. Such {\em
generalized programs (gPs)\/} have interesting
properties, for example, the ability to express
infinity axioms. We restrict the syntax of gPs such
that both rules and generalized literals are {\em
guarded}. Via a translation to guarded fixed-point
logic, we deduce 2-EXPTIME-completeness of
satisfiability checking in such {\em guarded gPs\/}
(GgPs). {\em Bound GgPs\/} are restricted GgPs with
EXPTIME-complete satisfiability checking, but still
sufficiently expressive to optimally simulate {\em
computation tree logic\/} (CTL). We translate Datalog
lite programs to GgPs, establishing equivalence of GgPs
under an open answer set semantics, alternation-free
$\mu$GF, and Datalog LITE.",
acknowledgement = ack-nhfb,
articleno = "26",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "answer set programming; fixed-point logic; open
domains",
}
@Article{Shen:2008:RRL,
author = "Yi-Dong Shen",
title = "Reasoning with recursive loops under the {PLP}
framework",
journal = j-TOCL,
volume = "9",
number = "4",
pages = "27:1--27:??",
month = aug,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1380572.1380576",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Aug 29 14:02:20 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Recursive loops in a logic program present a
challenging problem to the PLP (Probabilistic Logic
Programming) framework. On the one hand, they loop
forever so that the PLP backward-chaining inferences
would never stop. On the other hand, they may generate
cyclic influences, which are disallowed in Bayesian
networks. Therefore, in existing PLP approaches, logic
programs with recursive loops are considered to be
problematic and thus are excluded. In this article, we
propose a novel solution to this problem by making use
of recursive loops to build a stationary dynamic
Bayesian network. We introduce a new PLP formalism,
called a {\em Bayesian knowledge base}. It allows
recursive loops and contains logic clauses of the form
$A \leftarrow A_1, \ldots, A_l$, {\em true}, {\em
Context}, {\em Types}, which naturally formulate the
knowledge that the $A_i$'s have direct influences on
$A$ in the context {\em Context\/} under the type
constraints {\em Types}. We use the well-founded model
of a logic program to define the direct influence
relation and apply SLG-resolution to compute the space
of random variables together with their parental
connections. This establishes a clear declarative
semantics for a Bayesian knowledge base. We view a
logic program with recursive loops as a special
temporal model, where backward-chaining cycles of the
form $A \leftarrow \ldots A \leftarrow \ldots{}$ are
interpreted as feedbacks. This extends existing PLP
approaches, which mainly aim at (nontemporal)
relational models.",
acknowledgement = ack-nhfb,
articleno = "27",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Bayesian networks; cyclic influences; logic
programming; recursive loops; the well-founded model",
}
@Article{Seidl:2008:FOV,
author = "Helmut Seidl and Kumar Neeraj Verma",
title = "Flat and one-variable clauses: {Complexity} of
verifying cryptographic protocols with single blind
copying",
journal = j-TOCL,
volume = "9",
number = "4",
pages = "28:1--28:??",
month = aug,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1380572.1380577",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Aug 29 14:02:20 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Cryptographic protocols with single blind copying were
defined and modeled by Comon and Cortier using the new
class C of first-order clauses. They showed its
satisfiability problem to be in 3-DEXPTIME. We improve
this result by showing that satisfiability for this
class is NEXPTIME-complete, using new resolution
techniques. We show satisfiability to be
DEXPTIME-complete if clauses are Horn, which is what is
required for modeling cryptographic protocols. While
translation to Horn clauses only gives a DEXPTIME upper
bound for the secrecy problem for these protocols, we
further show that this secrecy problem is actually
DEXPTIME-complete.",
acknowledgement = ack-nhfb,
articleno = "28",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "cryptographic protocols; first-order logic; Horn
clauses; instantiation-based theorem proving;
resolution",
}
@Article{Alberti:2008:VAI,
author = "Marco Alberti and Federico Chesani and Marco Gavanelli
and Evelina Lamma and Paola Mello and Paolo Torroni",
title = "Verifiable agent interaction in abductive logic
programming: {The SCIFF} framework",
journal = j-TOCL,
volume = "9",
number = "4",
pages = "29:1--29:??",
month = aug,
year = "2008",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1380572.1380578",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri Aug 29 14:02:20 MDT 2008",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "SCIFF is a framework thought to specify and verify
interaction in open agent societies. The SCIFF language
is equipped with a semantics based on abductive logic
programming; SCIFF's operational component is a new
abductive logic programming proof procedure, also named
SCIFF, for reasoning with expectations in dynamic
environments. In this article we present the
declarative and operational semantics of the SCIFF
language, and the termination, soundness, and
completeness results of the SCIFF proof procedure, and
we demonstrate SCIFF's possible application in the
multiagent domain.",
acknowledgement = ack-nhfb,
articleno = "29",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "abductive logic programming; agent interaction
protocols; declarative semantics; formal properties;
IFF proof procedure; proof-procedures; SCIFF; SOCS
(SOcieties of ComputeeS)",
}
@Article{Artikis:2009:SNG,
author = "Alexander Artikis and Marek Sergot and Jeremy Pitt",
title = "Specifying norm-governed computational societies",
journal = j-TOCL,
volume = "10",
number = "1",
pages = "1:1--1:??",
month = jan,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1459010.1459011",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jan 26 18:05:23 MST 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Electronic markets, dispute resolution and negotiation
protocols are three types of application domains that
can be viewed as open agent societies. Key
characteristics of such societies are agent
heterogeneity, conflicting individual goals and
unpredictable behavior. Members of such societies may
fail to, or even choose not to, conform to the norms
governing their interactions. It has been argued that
systems of this type should have a formal, declarative,
verifiable, and meaningful semantics. We present a
theoretical and computational framework being developed
for the executable specification of open agent
societies. We adopt an external perspective and view
societies as instances of normative systems. In this
article, we demonstrate how the framework can be
applied to specifying and executing a contract-net
protocol. The specification is formalized in two action
languages, the $C+$ language and the Event Calculus,
and executed using respective software implementations,
the Causal Calculator and the Society Visualizer. We
evaluate our executable specification in the light of
the presented case study, discussing the strengths and
weaknesses of the employed action languages for the
specification of open agent societies.",
acknowledgement = ack-nhfb,
articleno = "1",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Action language; agent; contract-net; event calculus;
executable specification; norm; policy",
}
@Article{VanDenDries:2009:AC,
author = "Lou {Van Den Dries} and Yiannis N. Moschovakis",
title = "Arithmetic complexity",
journal = j-TOCL,
volume = "10",
number = "1",
pages = "2:1--2:??",
month = jan,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1459010.1459012",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jan 26 18:05:23 MST 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We obtain {\em lower bounds\/} on the cost of
computing various arithmetic functions and deciding
various arithmetic relations from specified primitives.
This includes lower bounds for computing the greatest
common divisor and deciding coprimeness of two
integers, from primitives like addition, subtraction,
division with remainder and multiplication. Some of our
results are in terms of recursive programs, but they
generalize directly to most (plausibly all) algorithms
from the specified primitives. Our methods involve some
elementary number theory as well as the development of
some basic notions and facts about recursive
algorithms.",
acknowledgement = ack-nhfb,
articleno = "2",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "coprimeness; greatest common divisor; Lower bounds for
arithmetical problems; recursive programs",
}
@Article{Yorke-Smith:2009:CCR,
author = "Neil Yorke-Smith and Carmen Gervet",
title = "Certainty closure: Reliable constraint reasoning with
incomplete or erroneous data",
journal = j-TOCL,
volume = "10",
number = "1",
pages = "3:1--3:??",
month = jan,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1459010.1459013",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jan 26 18:05:23 MST 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Constraint Programming (CP) has proved an effective
paradigm to model and solve difficult combinatorial
satisfaction and optimization problems from disparate
domains. Many such problems arising from the commercial
world are permeated by data uncertainty. Existing CP
approaches that accommodate uncertainty are less suited
to uncertainty arising due to incomplete and erroneous
data, because they do not build reliable models and
solutions guaranteed to address the user's genuine
problem as she perceives it. Other fields such as
reliable computation offer combinations of models and
associated methods to handle these types of uncertain
data, but lack an expressive framework characterizing
the resolution methodology independently of the
model.\par
We present a unifying framework that extends the CP
formalism in both model and solutions, to tackle
ill-defined combinatorial problems with incomplete or
erroneous data. The {\em certainty closure framework\/}
brings together modeling and solving methodologies from
different fields into the CP paradigm to provide
reliable and efficient approaches for uncertain
constraint problems. We demonstrate the applicability
of the framework on a case study in network diagnosis.
We define resolution forms that give generic templates,
and their associated operational semantics, to derive
practical solution methods for reliable solutions.",
acknowledgement = ack-nhfb,
articleno = "3",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "closure; Incomplete and erroneous data; reliable
solutions; uncertain constraint satisfaction problem",
}
@Article{Armando:2009:NRR,
author = "Alessandro Armando and Maria Paola Bonacina and Silvio
Ranise and Stephan Schulz",
title = "New results on rewrite-based satisfiability
procedures",
journal = j-TOCL,
volume = "10",
number = "1",
pages = "4:1--4:??",
month = jan,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1459010.1459014",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jan 26 18:05:23 MST 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Program analysis and verification require decision
procedures to reason on theories of data structures.
Many problems can be reduced to the {\em
satisfiability\/} of sets of {\em ground literals\/} in
theory $T$. If a sound and complete inference system
for first-order logic is guaranteed to {\em
terminate\/} on {\em T-satisfiability problems}, any
theorem-proving strategy with that system and a fair
search plan is a {\em T-satisfiability procedure}. We
prove termination of a rewrite-based first-order engine
on the theories of {\em records}, {\em integer
offsets}, {\em integer offsets modulo\/} and {\em
lists}. We give a {\em modularity theorem\/} stating
sufficient conditions for termination on a {\em
combination of theories}, given termination on each.
The above theories, as well as others, satisfy these
conditions. We introduce several sets of benchmarks on
these theories and their combinations, including both
{\em parametric\/} synthetic benchmarks to test {\em
scalability}, and real-world problems to test
performances on huge sets of literals. We compare the
rewrite-based theorem prover $E$ with the validity
checkers CVC and CVC Lite. Contrary to the folklore
that a general-purpose prover cannot compete with
reasoners with built-in theories, the experiments are
overall favorable to the theorem prover, showing that
not only the rewriting approach is elegant and
conceptually simple, but has important practical
implications.",
acknowledgement = ack-nhfb,
articleno = "4",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Automated reasoning; combination of theories; decision
procedures; inference; rewriting; satisfiability modulo
a theory; scalability; superposition; termination",
}
@Article{Iocchi:2009:RAA,
author = "Luca Iocchi and Thomas Lukasiewicz and Daniele Nardi
and Riccardo Rosati",
title = "Reasoning about actions with sensing under qualitative
and probabilistic uncertainty",
journal = j-TOCL,
volume = "10",
number = "1",
pages = "5:1--5:??",
month = jan,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1459010.1459015",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jan 26 18:05:23 MST 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We focus on the aspect of sensing in reasoning about
actions under qualitative and probabilistic
uncertainty. We first define the action language $E$
for reasoning about actions with sensing, which has a
semantics based on the autoepistemic description logic
{\em ALCK$_{\mbox{NF}}$}, and which is given a formal
semantics via a system of deterministic transitions
between epistemic states. As an important feature, the
main computational tasks in $E$ can be done in linear
and quadratic time. We then introduce the action
language $E+$ for reasoning about actions with sensing
under qualitative and probabilistic uncertainty, which
is an extension of $E$ by actions with nondeterministic
and probabilistic effects, and which is given a formal
semantics in a system of deterministic,
nondeterministic, and probabilistic transitions between
epistemic states. We also define the notion of a belief
graph, which represents the belief state of an agent
after a sequence of deterministic, nondeterministic,
and probabilistic actions, and which compactly
represents a set of unnormalized probability
distributions. Using belief graphs, we then introduce
the notion of a conditional plan and its goodness for
reasoning about actions under qualitative and
probabilistic uncertainty. We formulate the problems of
optimal and threshold conditional planning under
qualitative and probabilistic uncertainty, and show
that they are both uncomputable in general. We then
give two algorithms for conditional planning in our
framework. The first one is always sound, and it is
also complete for the special case in which the
relevant transitions between epistemic states are
cycle-free. The second algorithm is a sound and
complete solution to the problem of finite-horizon
conditional planning in our framework. Under suitable
assumptions, it computes every optimal finite-horizon
conditional plan in polynomial time. We also describe
an application of our formalism in a robotic-soccer
scenario, which underlines its usefulness in realistic
applications.",
acknowledgement = ack-nhfb,
articleno = "5",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "action languages; description logics; imprecise
probabilities; qualitative and probabilistic
uncertainty; Reasoning about actions; sensing",
}
@Article{Aceto:2009:FEB,
author = "Luca Aceto and Wan Fokkink and Anna Ingolfsdottir and
Bas Luttik",
title = "A finite equational base for {CCS} with left merge and
communication merge",
journal = j-TOCL,
volume = "10",
number = "1",
pages = "6:1--6:??",
month = jan,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1459010.1459016",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jan 26 18:05:23 MST 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Using the left merge and the communication merge from
ACP, we present an equational base (i.e., a
ground-complete and $\omega$-complete set of valid
equations) for the fragment of CCS without recursion,
restriction and relabeling modulo (strong)
bisimilarity. Our equational base is finite if the set
of actions is finite.",
acknowledgement = ack-nhfb,
articleno = "6",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Bisimilarity; CCS; communication merge; concurrency;
finite equational base; handshaking; left merge;
parallel composition; process algebra",
}
@Article{Kontinen:2009:LCC,
author = "Juha Kontinen",
title = "A logical characterization of the counting hierarchy",
journal = j-TOCL,
volume = "10",
number = "1",
pages = "7:1--7:??",
month = jan,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1459010.1459017",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Jan 26 18:05:23 MST 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In this article we give a logical characterization of
the counting hierarchy. The counting hierarchy is the
analogue of the polynomial hierarchy, the building
block being Probabilistic polynomial time PP instead of
NP. We show that the extension of first-order logic by
second-order majority quantifiers of all arities
describes exactly the problems in the counting
hierarchy. We also consider extending the
characterization to general proportional quantifiers
$Q^k_r$ interpreted as ``more than an $r$-fraction of
$k$-ary relations''. We show that the result holds for
rational numbers of the form $s/2^m$ but for any other
$0 < r < 1$, the corresponding logic satisfies the 0-1
law.",
acknowledgement = ack-nhfb,
articleno = "7",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Counting hierarchy; majority quantifiers; quantifier
elimination; the 0-1 law",
}
@Article{DalLago:2009:GLH,
author = "Ugo {Dal Lago}",
title = "The geometry of linear higher-order recursion",
journal = j-TOCL,
volume = "10",
number = "2",
pages = "8:1--8:??",
month = feb,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1462179.1462180",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Feb 25 22:28:54 MST 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Imposing linearity and ramification constraints allows
to weaken higher-order (primitive) recursion in such a
way that the class of representable functions equals
the class of polynomial-time computable functions, as
the works by Leivant, Hofmann, and others show. This
article shows that fine-tuning these two constraints
leads to different expressive strengths, some of them
lying well beyond polynomial time. This is done by
introducing a new semantics, called algebraic context
semantics. The framework stems from Gonthier's original
work (itself a model of Girard's geometry of
interaction) and turns out to be a versatile and
powerful tool for the quantitative analysis of
normalization in the lambda calculus with constants and
higher-order recursion.",
acknowledgement = ack-nhfb,
articleno = "8",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Geometry of interaction; higher-order recursion;
implicit computational complexity; lambda calculus;
type systems",
}
@Article{Lanotte:2009:PBC,
author = "Ruggero Lanotte and Simone Tini",
title = "Probabilistic bisimulation as a congruence",
journal = j-TOCL,
volume = "10",
number = "2",
pages = "9:1--9:??",
month = feb,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1462179.1462181",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Feb 25 22:28:54 MST 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We propose both an SOS transition rule format for the
generative model of probabilistic processes, and an SOS
transition rule format for the reactive model of the
probabilistic processes. Our rule formats guarantee
that probabilistic bisimulation is a congruence with
respect to process algebra operations. Moreover, our
rule format for generative process algebras guarantees
that the probability of the moves of a given process,
if there are any, sum up to 1, and the rule format for
reactive process algebras guarantees that the
probability of the moves of a given process labeled
with the same action, if there are any, sum up to 1. We
show that most operations of the probabilistic process
algebras studied in the literature are captured by our
formats, which, therefore, have practical
applications.",
acknowledgement = ack-nhfb,
articleno = "9",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Bisimulation; congruence; probabilistic process
algebra; transition rule format",
}
@Article{Gnaedig:2009:TRU,
author = "Isabelle Gnaedig and H{\'e}l{\`e}ne Kirchner",
title = "Termination of rewriting under strategies",
journal = j-TOCL,
volume = "10",
number = "2",
pages = "10:1--10:??",
month = feb,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1462179.1462182",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Feb 25 22:28:54 MST 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A termination proof method for rewriting under
strategies, based on an explicit induction on the
termination property, is presented and instantiated for
the innermost, outermost, and local strategies.
Rewriting trees are simulated by proof trees generated
with an abstraction mechanism, narrowing and
constraints representing sets of ground terms.
Abstraction introduces variables to represent normal
forms without computing them and to control the
narrowing mechanism, well known to easily diverge. The
induction ordering is not given a priori, but defined
with ordering constraints, incrementally set during the
proof. It is established that termination under
strategy is equivalent to the construction of finite
proof trees schematizing terminating rewriting trees.
Sufficient effective conditions to ensure finiteness
are studied and the method is illustrated on several
examples for each specific strategy.",
acknowledgement = ack-nhfb,
articleno = "10",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Abstraction; induction; innermost; local strategy;
narrowing; ordering constraint; outermost;
termination",
}
@Article{Gabbrielli:2009:CSC,
author = "Maurizio Gabbrielli and Maria Chiara Meo",
title = "A compositional semantics for {CHR}",
journal = j-TOCL,
volume = "10",
number = "2",
pages = "11:1--11:??",
month = feb,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1462179.1462183",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Feb 25 22:28:54 MST 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Constraint Handling Rules (CHR) is a committed-choice
declarative language which has been designed for
writing constraint solvers. A CHR program consists of
multiheaded guarded rules which allow to rewrite
constraints into simpler ones until a solved form is
reached.\par
CHR has received considerable attention, both from the
practical and from the theoretical side. Nevertheless,
due the use of multiheaded clauses, there are several
aspects of the CHR semantics which have not been
clarified yet. In particular, no compositional
semantics for CHR has been defined so far.\par
In this article we introduce a fix-point semantics
which characterizes the input/output behavior of a CHR
program and which is and-compositional, that is, which
allows to retrieve the semantics of a conjunctive query
from the semantics of its components. Such a semantics
can be used as a basis to define incremental and
modular analysis and verification tools.",
acknowledgement = ack-nhfb,
articleno = "11",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Semantics",
}
@Article{Guerrini:2009:PTC,
author = "Stefano Guerrini and Andrea Masini",
title = "Proofs, tests and continuation passing style",
journal = j-TOCL,
volume = "10",
number = "2",
pages = "12:1--12:??",
month = feb,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1462179.1462184",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Feb 25 22:28:54 MST 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The concept of syntactical {\em duality\/} is central
in logic. In particular, the duality defined by
classical negation, or more syntactically by left and
right in sequents, has been widely used to relate logic
and computations. We study the proof/test duality
proposed by Girard in his 1999 paper on the meaning of
logical rules. In detail, starting from the notion of
``test'' proposed by Girard, we develop a notion of
test for intuitionistic logic and we give a complete
deductive system whose computational interpretation is
the target language of the call-by-value and
call-by-name continuation passing style translations.",
acknowledgement = ack-nhfb,
articleno = "12",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "call-by-name; call-by-value; continuations passing
style; intutionistic logic; lambda calculus; linear
logic; Minimal logic",
}
@Article{Schroder:2009:PBR,
author = "Lutz Schr{\"o}der and Dirk Pattinson",
title = "{PSPACE} bounds for rank-1 modal logics",
journal = j-TOCL,
volume = "10",
number = "2",
pages = "13:1--13:??",
month = feb,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1462179.1462185",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Feb 25 22:28:54 MST 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "For lack of general algorithmic methods that apply to
wide classes of logics, establishing a complexity bound
for a given modal logic is often a laborious task. The
present work is a step towards a general theory of the
complexity of modal logics. Our main result is that all
rank-1 logics enjoy a shallow model property and thus
are, under mild assumptions on the format of their
axiomatisation, in {\em PSPACE}. This leads to a
unified derivation of tight {\em PSPACE\/} -bounds for
a number of logics, including $K$, $KD$, coalition
logic, graded modal logic, majority logic, and
probabilistic modal logic. Our generic algorithm
moreover finds tableau proofs that witness pleasant
proof-theoretic properties including a weak subformula
property. This generality is made possible by a
coalgebraic semantics, which conveniently abstracts
from the details of a given model class and thus allows
covering a broad range of logics in a uniform way.",
acknowledgement = ack-nhfb,
articleno = "13",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "coalgebra; resolution; Shallow models",
}
@Article{Bruscoli:2009:PCD,
author = "Paola Bruscoli and Alessio Guglielmi",
title = "On the proof complexity of deep inference",
journal = j-TOCL,
volume = "10",
number = "2",
pages = "14:1--14:??",
month = feb,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1462179.1462186",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Feb 25 22:28:54 MST 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We obtain two results about the proof complexity of
deep inference: (1) Deep-inference proof systems are as
powerful as Frege ones, even when both are extended
with the Tseitin extension rule or with the
substitution rule; (2) there are analytic
deep-inference proof systems that exhibit an
exponential speedup over analytic Gentzen proof systems
that they polynomially simulate.",
acknowledgement = ack-nhfb,
articleno = "14",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Analyticity; calculus of structures; deep inference;
Frege systems; Statman tautologies",
}
@Article{Tripakis:2009:CTB,
author = "Stavros Tripakis",
title = "Checking timed {B{\"u}chi} automata emptiness on
simulation graphs",
journal = j-TOCL,
volume = "10",
number = "3",
pages = "15:1--15:??",
month = apr,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1507244.1507245",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Apr 13 08:54:35 MDT 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Timed automata [Alur and Dill 1994] comprise a popular
model for describing real-time and embedded systems and
reasoning formally about them. Efficient model-checking
algorithms have been developed and implemented in tools
such as Kronos [Daws et al. 1996] or Uppaal [Larsen et
al. 1997] for checking safety properties on this model,
which amounts to reachability. These algorithms use the
so-called zone-closed simulation graph, a finite graph
that admits efficient representation and has been
recently shown to preserve reachability [Bouyer 2004].
Building upon Bouyer [2004] and our previous work
[Bouajjani et al. 1997; Tripakis et al. 2005], we show
that this graph can also be used for checking liveness
properties, in particular, emptiness of timed B{\"u}chi
automata.",
acknowledgement = ack-nhfb,
articleno = "15",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "chi automata; Formal methods; model checking;
property-preserving abstractions; specification
languages; timed Bü",
}
@Article{Demri:2009:LFQ,
author = "St{\'e}phane Demri and Ranko Lazi{\'c}",
title = "{LTL} with the freeze quantifier and register
automata",
journal = j-TOCL,
volume = "10",
number = "3",
pages = "16:1--16:??",
month = apr,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1507244.1507246",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Apr 13 08:54:35 MDT 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A data word is a sequence of pairs of a letter from a
finite alphabet and an element from an infinite set,
where the latter can only be compared for equality. To
reason about data words, linear temporal logic is
extended by the freeze quantifier, which stores the
element at the current word position into a register,
for equality comparisons deeper in the formula. By
translations from the logic to alternating automata
with registers and then to faulty counter automata
whose counters may erroneously increase at any time,
and from faulty and error-free counter automata to the
logic, we obtain a complete complexity table for
logical fragments defined by varying the set of
temporal operators and the number of registers. In
particular, the logic with future-time operators and 1
register is decidable but not primitive recursive over
finite data words. Adding past-time operators or 1 more
register, or switching to infinite data words, causes
undecidability.",
acknowledgement = ack-nhfb,
articleno = "16",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Computational complexity; expressiveness",
}
@Article{Bordeaux:2009:GCO,
author = "Lucas Bordeaux and Marco Cadoli and Toni Mancini",
title = "Generalizing consistency and other constraint
properties to quantified constraints",
journal = j-TOCL,
volume = "10",
number = "3",
pages = "17:1--17:??",
month = apr,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1507244.1507247",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Apr 13 08:54:35 MDT 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Quantified constraints and Quantified Boolean Formulae
are typically much more difficult to reason with than
classical constraints, because quantifier alternation
makes the usual notion of {\em solution\/}
inappropriate. As a consequence, basic properties of
Constraint Satisfaction Problems (CSPs), such as
consistency or substitutability, are not completely
understood in the quantified case. These properties are
important because they are the basis of most of the
reasoning methods used to solve classical
(existentially quantified) constraints, and it is
desirable to benefit from similar reasoning methods in
the resolution of quantified constraints.\par
In this article, we show that most of the properties
that are used by solvers for CSP can be generalized to
quantified CSP. This requires a rethinking of a number
of basic concepts; in particular, we propose a notion
of {\em outcome\/} that generalizes the classical
notion of solution and on which all definitions are
based. We propose a systematic study of the relations
which hold between these properties, as well as
complexity results regarding the decision of these
properties. Finally, and since these problems are
typically intractable, we generalize the approach used
in CSP and propose weaker, easier to check notions
based on {\em locality}, which allow to detect these
properties incompletely but in polynomial time.",
acknowledgement = ack-nhfb,
articleno = "17",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Constraint satisfaction; quantified Boolean formulae;
quantified constraints",
}
@Article{Giordano:2009:ATC,
author = "Laura Giordano and Valentina Gliozzi and Nicola
Olivetti and Gian Luca Pozzato",
title = "Analytic tableaux calculi for {KLM} logics of
nonmonotonic reasoning",
journal = j-TOCL,
volume = "10",
number = "3",
pages = "18:1--18:??",
month = apr,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1507244.1507248",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Apr 13 08:54:35 MDT 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present tableau calculi for the logics of
nonmonotonic reasoning defined by Kraus, Lehmann and
Magidor (KLM). We give a tableau proof procedure for
all KLM logics, namely preferential, loop-cumulative,
cumulative, and rational logics. Our calculi are
obtained by introducing suitable modalities to
interpret conditional assertions. We provide a decision
procedure for the logics considered and we study their
complexity.",
acknowledgement = ack-nhfb,
articleno = "18",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Analytic tableaux calculi; nonmonotonic reasoning",
}
@Article{Ying:2009:AQP,
author = "Mingsheng Ying and Yuan Feng and Runyao Duan and
Zhengfeng Ji",
title = "An algebra of quantum processes",
journal = j-TOCL,
volume = "10",
number = "3",
pages = "19:1--19:??",
month = apr,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1507244.1507249",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Apr 13 08:54:35 MDT 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We introduce an algebra qCCS of pure quantum processes
in which communications by moving quantum states
physically are allowed and computations are modeled by
super-operators, but no classical data is explicitly
involved. An operational semantics of qCCS is presented
in terms of (nonprobabilistic) labeled transition
systems. Strong bisimulation between processes modeled
in qCCS is defined, and its fundamental algebraic
properties are established, including uniqueness of the
solutions of recursive equations. To model sequential
computation in qCCS, a reduction relation between
processes is defined. By combining reduction relation
and strong bisimulation we introduce the notion of
strong reduction-bisimulation, which is a device for
observing interaction of computation and communication
in quantum systems. Finally, a notion of strong
approximate bisimulation (equivalently, strong
bisimulation distance) and its reduction counterpart
are introduced. It is proved that both approximate
bisimilarity and approximate reduction-bisimilarity are
preserved by various constructors of quantum processes.
This provides us with a formal tool for observing
robustness of quantum processes against inaccuracy in
the implementation of its elementary gates.",
acknowledgement = ack-nhfb,
articleno = "19",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "bisimulation; process algebra; quantum communication;
Quantum computation; super-operator",
}
@Article{Bouhoula:2009:SCC,
author = "Adel Bouhoula",
title = "Simultaneous checking of completeness and ground
confluence for algebraic specifications",
journal = j-TOCL,
volume = "10",
number = "3",
pages = "20:1--20:??",
month = apr,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1507244.1507250",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Apr 13 08:54:35 MDT 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Algebraic specifications provide a powerful method for
the specification of abstract data types in programming
languages and software systems. Completeness and ground
confluence are fundamental notions for building
algebraic specifications in a correct and modular way.
Related works for checking ground confluence are based
on the completion techniques or on the test that all
critical pairs between axioms are valid with respect to
a sufficient criterion for ground confluence. It is
generally accepted that such techniques may be very
inefficient, even for very small specifications.
Indeed, the completion procedure often diverges and
there often exist many critical pairs of the axioms. In
this article, we present a procedure for simultaneously
checking completeness and ground confluence for
specifications with free/nonfree constructors and
parameterized specifications. If the specification is
not complete or not ground confluent, then our
procedure will output the set of patterns on whose
ground instances a function is not defined and it can
easily identify the rules that break ground confluence.
In contrast to previous work, our method does not rely
on completion techniques and does not require the
computation of critical pairs of the axioms. The method
is entirely implemented and allowed us to prove the
completeness and the ground confluence of many
specifications in a completely automatic way, where
related techniques diverge or generate very complex
proofs. Our system offers two main components: (i) a
completeness and ground confluence analyzer that
computes pattern trees of defined functions and may
generate some proof obligations; and (ii) a procedure
to prove (joinable) inductive conjectures which is used
to discharge these proof obligations.",
acknowledgement = ack-nhfb,
articleno = "20",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "algebraic specifications; Automated deduction;
completeness; ground confluence; parameterization; term
rewriting systems",
}
@Article{Giordano:2009:TCP,
author = "Laura Giordano and Valentina Gliozzi and Nicola
Olivetti and Camilla Schwind",
title = "Tableau calculus for preference-based conditional
logics: {PCL} and its extensions",
journal = j-TOCL,
volume = "10",
number = "3",
pages = "21:1--21:??",
month = apr,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1507244.1507251",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Apr 13 08:54:35 MDT 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present a tableau calculus for some fundamental
systems of propositional conditional logics. We
consider the conditional logics that can be
characterized by {\em preferential\/} semantics (i.e.,
possible world structures equipped with a family of
preference relations). For these logics, we provide a
uniform completeness proof of the axiomatization with
respect to the semantics, and a uniform labeled tableau
procedure.",
acknowledgement = ack-nhfb,
articleno = "21",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "conditional logics; Tableaux calculi",
}
@Article{Kawamura:2009:DR,
author = "Akitoshi Kawamura",
title = "Differential recursion",
journal = j-TOCL,
volume = "10",
number = "3",
pages = "22:1--22:??",
month = apr,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1507244.1507252",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Mon Apr 13 08:54:35 MDT 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present a redevelopment of the theory of
real-valued recursive functions that was introduced by
C. Moore in 1996 by analogy with the standard
formulation of the integer-valued recursive functions.
While his work opened a new line of research on analog
computation, the original paper contained some
technical inaccuracies. We discuss possible attempts to
remove the ambiguity in the behavior of the operators
on partial functions, with a focus on his ``primitive
recursive'' functions generated by the {\em
differential recursion\/} operator that solves initial
value problems. Under a reasonable reformulation, the
functions in this class are shown to be analytic and
computable in a strong sense in computable analysis.
Despite this well-behavedness, the class turns out to
be too big to have the originally purported relation to
differentially algebraic functions, and hence to C. E.
Shannon's model of analog computation.",
acknowledgement = ack-nhfb,
articleno = "22",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Analog computation; differentially algebraic
functions; initial value problems; real recursive
functions; transcendentally transcendental functions",
}
@Article{Baillot:2009:GES,
author = "Patrick Baillot and Jean-Yves Marion and Simona Ronchi
Della Rocca",
title = "Guest editorial: {Special} issue on implicit
computational complexity",
journal = j-TOCL,
volume = "10",
number = "4",
pages = "23:1--23:??",
month = aug,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1555746.1555747",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Aug 11 12:46:55 MDT 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "23",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Arai:2009:NFA,
author = "Toshiyasu Arai and Naohi Eguchi",
title = "A new function algebra of {EXPTIME} functions by safe
nested recursion",
journal = j-TOCL,
volume = "10",
number = "4",
pages = "24:1--24:??",
month = aug,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1555746.1555748",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Aug 11 12:46:55 MDT 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Bellantoni and Cook have given a function-algebra
characterization of the polynomial-time computable
functions via an unbounded recursion scheme which is
called safe recursion. Inspired by their work, we
characterize the exponential-time computable functions
with the use of a safe variant of nested recursion.",
acknowledgement = ack-nhfb,
articleno = "24",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "EXPTIME; implicit computational complexity",
}
@Article{DalLago:2009:CSL,
author = "Ugo {Dal Lago}",
title = "Context semantics, linear logic, and computational
complexity",
journal = j-TOCL,
volume = "10",
number = "4",
pages = "25:1--25:??",
month = aug,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1555746.1555749",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Aug 11 12:46:55 MDT 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We show that context semantics can be fruitfully
applied to the quantitative analysis of proof
normalization in linear logic. In particular, context
semantics lets us define the {\em weight\/} of a
proof-net as a measure of its inherent complexity: it
is both an upper bound to normalization time (modulo a
polynomial overhead, independently on the reduction
strategy) and a lower bound to the amount of resources
needed to compute the normal form. Weights are then
exploited in proving strong soundness theorems for
various subsystems of linear logic, namely elementary
linear logic, soft linear logic, and light linear
logic.",
acknowledgement = ack-nhfb,
articleno = "25",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "geometry of interaction; implicit computational
complexity; linear logic",
}
@Article{Crolard:2009:ELL,
author = "Tristan Crolard and Emmanuel Polonowski and Pierre
Valarcher",
title = "Extending the loop language with higher-order
procedural variables",
journal = j-TOCL,
volume = "10",
number = "4",
pages = "26:1--26:??",
month = aug,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1555746.1555750",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Aug 11 12:46:55 MDT 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We extend Meyer and Ritchie's Loop language with
higher-order procedures and procedural variables and we
show that the resulting programming language (called
Loop$^\omega$) is a natural imperative counterpart of
G{\"o}del System T. The argument is two-fold:\par
(1) we define a translation of the Loop$^\omega$
language into System T and we prove that this
translation actually provides a lock-step
simulation,\par
(2) using a converse translation, we show that
Loop$^\omega$ is expressive enough to encode any term
of System T.\par
Moreover, we define the ``iteration rank'' of a
Loop$^\omega$ program, which corresponds to the
classical notion of ``recursion rank'' in System T, and
we show that both translations preserve ranks. Two
applications of these results in the area of implicit
complexity are described.",
acknowledgement = ack-nhfb,
articleno = "26",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "G{\"o}del System T; higher-order procedures; loop
language; procedural variables",
}
@Article{Marion:2009:SIS,
author = "Jean-Yves Marion and Romain P{\'e}choux",
title = "Sup-interpretations, a semantic method for static
analysis of program resources",
journal = j-TOCL,
volume = "10",
number = "4",
pages = "27:1--27:??",
month = aug,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1555746.1555751",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Aug 11 12:46:55 MDT 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The sup-interpretation method is proposed as a new
tool to control memory resources of first order
functional programs with pattern matching by static
analysis. It has been introduced in order to increase
the intensionality, that is the number of captured
algorithms, of a previous method, the
quasi-interpretations. Basically, a sup-interpretation
provides an upper bound on the size of function
outputs. A criterion, which can be applied to
terminating as well as nonterminating programs, is
developed in order to bound the stack frame size
polynomially. Since this work is related to
quasi-interpretation, dependency pairs, and size-change
principle methods, we compare these notions obtaining
several results. The first result is that, given any
program, we have heuristics for finding a
sup-interpretation when we consider polynomials of
bounded degree. Another result consists in the
characterizations of the sets of functions computable
in polynomial time and in polynomial space. A last
result consists in applications of sup-interpretations
to the dependency pair and the size-change principle
methods.",
acknowledgement = ack-nhfb,
articleno = "27",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "resources control; static analysis of first-order
languages",
}
@Article{Jones:2009:FCM,
author = "Neil D. Jones and Lars Kristiansen",
title = "A flow calculus of {\em mwp\/}-bounds for complexity
analysis",
journal = j-TOCL,
volume = "10",
number = "4",
pages = "28:1--28:??",
month = aug,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1555746.1555752",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Aug 11 12:46:55 MDT 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present a method for certifying that the values
computed by an imperative program will be bounded by
polynomials in the program's inputs. To this end, we
introduce {\em mwp\/}-matrices and define a semantic
relation $\models C : M$, where $C$ is a program and
$M$ is an {\em mwp\/}-matrix. It follows
straightforwardly from our definitions that there
exists $M$ such that $\models C : M$ holds iff every
value computed by $C$ is bounded by a polynomial in the
inputs. Furthermore, we provide a syntactical proof
calculus and define the relation $\vdash C : M$ to hold
iff there exists a derivation in the calculus where $C
: M$ is the bottom line. We prove that $\vdash C : M$
implies $\models C : M$.\par
By means of exhaustive proof search, an algorithm can
decide if there exists $M$ such that the relation
$\vdash C : M$ holds, and thus, our results yield a
computational method.",
acknowledgement = ack-nhfb,
articleno = "28",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "automatable complexity analysis of imperative
programs; implicit computational complexity; static
program analysis",
}
@Article{Moyen:2009:RCG,
author = "Jean-Yves Moyen",
title = "Resource control graphs",
journal = j-TOCL,
volume = "10",
number = "4",
pages = "29:1--29:??",
month = aug,
year = "2009",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1555746.1555753",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Aug 11 12:46:55 MDT 2009",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Resource Control Graphs are an abstract representation
of programs. Each state of the program is abstracted by
its size, and each instruction is abstracted by the
effects it has on the state size whenever it is
executed. The abstractions of instruction effects are
then used as weights on the arcs of a program's Control
Flow Graph.\par
Termination is proved by finding decreases in a
well-founded order on state-size, in line with other
termination analyses, resulting in proofs similar in
spirit to those produced by Size Change Termination
analysis.\par
However, the size of states may also be used to measure
the amount of space consumed by the program at each
point of execution. This leads to an alternative
characterisation of the Non Size Increasing programs,
that is, of programs that can compute without
allocating new memory.\par
This new tool is able to encompass several existing
analyses and similarities with other studies,
suggesting that even more analyses might be expressible
in this framework, thus giving hopes for a generic tool
for studying programs.",
acknowledgement = ack-nhfb,
articleno = "29",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "implicit computational complexity; non-size increasing
computation; program analysis; program termination;
size change termination",
}
@Article{Chatterjee:2009:FWR,
author = "Krishnendu Chatterjee and Thomas A. Henzinger and
Florian Horn",
title = "Finitary winning in $\omega$-regular games",
journal = j-TOCL,
volume = "11",
number = "1",
pages = "1:1--1:??",
month = oct,
year = "2009",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Mar 16 08:57:54 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "1",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Schneider-Kamp:2009:ATP,
author = "Peter Schneider-Kamp and J{\"u}rgen Giesl and
Alexander Serebrenik and Ren{\'e} Thiemann",
title = "Automated termination proofs for logic programs by
term rewriting",
journal = j-TOCL,
volume = "11",
number = "1",
pages = "2:1--2:??",
month = oct,
year = "2009",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Mar 16 08:57:54 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "2",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Goranko:2009:TBD,
author = "Valentin Goranko and Dmitry Shkatov",
title = "Tableau-based decision procedures for logics of
strategic ability in multiagent systems",
journal = j-TOCL,
volume = "11",
number = "1",
pages = "3:1--3:??",
month = oct,
year = "2009",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Mar 16 08:57:54 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "3",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Benedikt:2009:RTL,
author = "Michael Benedikt and Luc Segoufin",
title = "Regular tree languages definable in {FO} and in
{FO$_{mod}$}",
journal = j-TOCL,
volume = "11",
number = "1",
pages = "4:1--4:??",
month = oct,
year = "2009",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Mar 16 08:57:54 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "4",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Guidi:2009:FS,
author = "Ferruccio Guidi",
title = "The formal system $\lambda \delta$",
journal = j-TOCL,
volume = "11",
number = "1",
pages = "5:1--5:??",
month = oct,
year = "2009",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Mar 16 08:57:54 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "5",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Pientka:2009:HOT,
author = "Brigitte Pientka",
title = "Higher-order term indexing using substitution trees",
journal = j-TOCL,
volume = "11",
number = "1",
pages = "6:1--6:??",
month = oct,
year = "2009",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Mar 16 08:57:54 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "6",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Arthan:2009:GFS,
author = "Rob Arthan and Ursula Martin and Erik A. Mathiesen and
Paulo Oliva",
title = "A general framework for sound and complete
{Floyd-Hoare} logics",
journal = j-TOCL,
volume = "11",
number = "1",
pages = "7:1--7:??",
month = oct,
year = "2009",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Mar 16 08:57:54 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "7",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bailey:2010:LQV,
author = "James Bailey and Guozhu Dong and Anthony Widjaja To",
title = "Logical queries over views: {Decidability} and
expressiveness",
journal = j-TOCL,
volume = "11",
number = "2",
pages = "8:1--8:??",
month = jan,
year = "2010",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Mar 16 08:57:57 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "8",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Comon-Lundh:2010:DSP,
author = "Hubert Comon-Lundh and V{\'e}ronique Cortier and Eugen
Z{\~a}linescu",
title = "Deciding security properties for cryptographic
protocols. Application to key cycles",
journal = j-TOCL,
volume = "11",
number = "2",
pages = "9:1--9:??",
month = jan,
year = "2010",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Mar 16 08:57:57 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "9",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Udrea:2010:AR,
author = "Octavian Udrea and Diego Reforgiato Recupero and V. S.
Subrahmanian",
title = "Annotated {RDF}",
journal = j-TOCL,
volume = "11",
number = "2",
pages = "10:1--10:??",
month = jan,
year = "2010",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Mar 16 08:57:57 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "10",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Adams:2010:WPC,
author = "Robin Adams and Zhaohui Luo",
title = "Weyl's predicative classical mathematics as a
logic-enriched type theory",
journal = j-TOCL,
volume = "11",
number = "2",
pages = "11:1--11:??",
month = jan,
year = "2010",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Mar 16 08:57:57 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "11",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Cosmadakis:2010:UIR,
author = "Stavros Cosmadakis and Eugenie Foustoucos and
Anastasios Sidiropoulos",
title = "Undecidability and intractability results concerning
datalog programs and their persistency numbers",
journal = j-TOCL,
volume = "11",
number = "2",
pages = "12:1--12:??",
month = jan,
year = "2010",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Mar 16 08:57:57 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "12",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Tiu:2010:PSS,
author = "Alwen Tiu and Dale Miller",
title = "Proof search specifications of bisimulation and modal
logics for the $\pi$-calculus",
journal = j-TOCL,
volume = "11",
number = "2",
pages = "13:1--13:??",
month = jan,
year = "2010",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Mar 16 08:57:57 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "13",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Eiter:2010:FDN,
author = "Thomas Eiter and Mantas {\v{S}}imkus",
title = "{FDNC}: {Decidable} nonmonotonic disjunctive logic
programs with function symbols",
journal = j-TOCL,
volume = "11",
number = "2",
pages = "14:1--14:??",
month = jan,
year = "2010",
CODEN = "????",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Mar 16 08:57:57 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "14",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bodirsky:2010:FAD,
author = "Manuel Bodirsky and Jan K{\'a}ra",
title = "A fast algorithm and datalog inexpressibility for
temporal reasoning",
journal = j-TOCL,
volume = "11",
number = "3",
pages = "15:1--15:??",
month = may,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1740582.1740583",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri May 14 15:42:49 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We introduce a new tractable temporal constraint
language, which strictly contains the Ord-Horn language
of B{\"u}rkert and Nebel and the class of AND/OR
precedence constraints. The algorithm we present for
this language decides whether a given set of
constraints is consistent in time that is quadratic in
the input size. We also prove that (unlike Ord-Horn)
the constraint satisfaction problem of this language
cannot be solved by Datalog or by establishing local
consistency.",
acknowledgement = ack-nhfb,
articleno = "15",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "algorithms; computational complexity; Constraint
satisfaction; Datalog; Ord-Horn; precedence
constraints; temporal reasoning",
}
@Article{Namjoshi:2010:CCR,
author = "Kedar S. Namjoshi and Richard J. Trefler",
title = "On the completeness of compositional reasoning
methods",
journal = j-TOCL,
volume = "11",
number = "3",
pages = "16:1--16:??",
month = may,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1740582.1740584",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri May 14 15:42:49 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Hardware systems and reactive software systems can be
described as the composition of several concurrently
active processes. Automated reasoning based on model
checking algorithms can substantially increase
confidence in the overall reliability of a system.
Direct methods for model checking a concurrent
composition, however, usually suffer from the explosion
in the number of program states that arises from
concurrency. Reasoning compositionally about individual
processes helps mitigate this problem. A number of
rules have been proposed for compositional reasoning,
typically based on an assume-guarantee reasoning
paradigm. Reasoning with these rules can be delicate,
as some are syntactically circular in nature, in that
assumptions and guarantees are mutually dependent. This
is known to be a source of unsoundness. In this
article, we investigate rules for compositional
reasoning from the viewpoint of {\em completeness}. We
show that several rules are incomplete: that is, there
are properties whose validity cannot be established
using (only) these rules. We derive a new, circular,
reasoning rule and show it to be sound and complete. We
show that the auxiliary assertions needed for
completeness need be defined only on the interface of
the component processes. We also show that the two main
paradigms of circular and noncircular reasoning are
closely related, in that a proof of one type can be
transformed in a straightforward manner to one of the
other type. These results give some insight into the
applicability of compositional reasoning methods.",
acknowledgement = ack-nhfb,
articleno = "16",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "assume-guarantee reasoning; automated reasoning;
Compositional reasoning; concurrent systems;
syntactically circular reasoning",
}
@Article{Kahler:2010:DSP,
author = "Detlef K{\"a}hler and Ralf K{\"u}sters and Thomas
Wilke",
title = "Deciding strategy properties of contract-signing
protocols",
journal = j-TOCL,
volume = "11",
number = "3",
pages = "17:1--17:??",
month = may,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1740582.1740585",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri May 14 15:42:49 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Research on the automatic analysis of cryptographic
protocols has so far concentrated on reachability
properties, such as secrecy and authentication. In this
article, we prove that certain game-theoretic security
properties, including balance for contract-signing
protocols, can be decided in a Dolev--Yao style model
with a bounded number of sessions. The decision
algorithm that we develop is based on standard
constraint-solving procedures, which, in the past, have
successfully been employed in tools for reachability
properties. Our result thus paves the way for extending
these tools to deal with game-theoretic security
properties.",
acknowledgement = ack-nhfb,
articleno = "17",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "automatic security analysis; Contract signing;
decidability",
}
@Article{Dershowitz:2010:CPP,
author = "Nachum Dershowitz and Iddo Tzameret",
title = "Complexity of propositional proofs under a promise",
journal = j-TOCL,
volume = "11",
number = "3",
pages = "18:1--18:??",
month = may,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1740582.1740586",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri May 14 15:42:49 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study --- within the framework of propositional
proof complexity --- the problem of certifying
unsatisfiability of CNF formulas under the promise that
any satisfiable formula has many satisfying
assignments, where {\em many\/} stands for an
explicitly specified function $\Lambda$ in the number
of variables {\em n}. To this end, we develop
propositional proof systems under different measures of
promises (i.e., different $\Lambda$) as extensions of
resolution. This is done by augmenting resolution with
axioms that, roughly, can eliminate sets of truth
assignments defined by Boolean circuits. We then
investigate the complexity of such systems, obtaining
an exponential separation in the average case between
resolution under different size promises:\par
(1) Resolution has polynomial-size refutations for all
unsatisfiable 3CNF formulas when the promise is
$\epsilon \cdot 2^n$, for any constant 0\par
(2) There are no subexponential size resolution
refutations for random 3CNF formulas, when the promise
is $2^\delta n$, for any constant 0\par
``{\em Goods Satisfactory or Money Refunded\/}''\par
--- The Eaton Promise",
acknowledgement = ack-nhfb,
articleno = "18",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Promise problems; propositional proof complexity;
random 3CNF; resolution",
}
@Article{Ben-Sasson:2010:LBB,
author = "Eli Ben-Sasson and Prahladh Harsha",
title = "Lower bounds for bounded depth {Frege} proofs via
{Pudl{\'a}k--Buss} games",
journal = j-TOCL,
volume = "11",
number = "3",
pages = "19:1--19:??",
month = may,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1740582.1740587",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri May 14 15:42:49 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present a simple proof of the bounded-depth Frege
proof lower bounds of Pitassi et al. [1993] and
Kraj{\'\i}{\v{c}}ek et al. [1995] for the pigeonhole
principle. Our method uses the interpretation of proofs
as two player games given by Pudl{\'a}k and Buss. Our
lower bound is conceptually simpler than previous ones,
and relies on tools and intuition that are well known
in the context of computational complexity. This makes
the lower bound of Pitassi et al. [1993] and
Kraj{\'\i}{\v{c}}ek et al. [1995] accessible to the
general computational complexity audience. We hope this
new view will open new directions for research in proof
complexity.",
acknowledgement = ack-nhfb,
articleno = "19",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Frege proofs; lower bounds; pigeonhole principle;
Proof complexity",
}
@Article{Samer:2010:DLS,
author = "Marko Samer and Helmut Veith",
title = "On the distributivity of {LTL} specifications",
journal = j-TOCL,
volume = "11",
number = "3",
pages = "20:1--20:??",
month = may,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1740582.1740588",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Fri May 14 15:42:49 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In this article, we investigate LTL specifications
where $\gamma[\varphi \wedge \psi]$ is equivalent to
$\gamma[\varphi ] \wedge \gamma[\psi]$ independent of
$\varphi$ and $\psi$. Formulas $\gamma$ with this
property are called {\em distributive queries\/}
because they naturally arise in Chan's seminal approach
to temporal logic query solving [Chan 2000]. As
recognizing distributive LTL queries is
PSpace-complete, we consider distributive fragments of
LTL defined by templates as in Buccafurri et al.
[2001]. Our main result is a syntactic characterization
of distributive LTL queries in terms of LTL templates:
we construct a context-free template grammar LTLQ$^x$
which guarantees that all specifications obtained from
LTLQ$^x$ are distributive, and all templates not
obtained from LTLQ$^x$ have simple nondistributive
instantiations.",
acknowledgement = ack-nhfb,
articleno = "20",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Constraint satisfaction; distributivity; LTL; query
solving; strongest solution; syntactic
characterization; template characterization; unique
solution",
}
@Article{Kaminski:2010:CSI,
author = "Michael Kaminski and Simone Martini",
title = "{CSL 2008} special issue",
journal = j-TOCL,
volume = "11",
number = "4",
pages = "21:1--21:??",
month = jul,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1805950.1805951",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Jul 15 18:17:23 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "21",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Beyersdorff:2010:TKL,
author = "Olaf Beyersdorff and Sebastian M{\"u}ller",
title = "A tight {Karp--Lipton} collapse result in bounded
arithmetic",
journal = j-TOCL,
volume = "11",
number = "4",
pages = "22:1--22:??",
month = jul,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1805950.1805952",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Jul 15 18:17:23 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Cook and Kraj{\'\i}{\v{c}}ek have recently obtained
the following Karp--Lipton collapse result in bounded
arithmetic: if the theory {\em PV\/} proves NP
$\subseteq$ P/ {\em poly}, then the polynomial
hierarchy collapses to the Boolean hierarchy, and this
collapse is provable in {\em PV}. Here we show the
converse implication, thus answering an open question
posed by Cook and Kraj{\'\i}{\v{c}}ek. We obtain this
result by formalizing in {\em PV\/} a hard/easy
argument of Buhrman et al. [2003].\par
In addition, we continue the investigation of
propositional proof systems using advice, initiated by
Cook and Kraj{\'\i}{\v{c}}ek. In particular, we obtain
several optimality results for proof systems using
advice. We further show that these optimal systems are
equivalent to natural extensions of Frege systems.",
acknowledgement = ack-nhfb,
articleno = "22",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "advice; bounded arithmetic; extended Frege;
Karp--Lipton theorem; optimal propositional proof
systems",
}
@Article{Chatterjee:2010:QL,
author = "Krishnendu Chatterjee and Laurent Doyen and Thomas A.
Henzinger",
title = "Quantitative languages",
journal = j-TOCL,
volume = "11",
number = "4",
pages = "23:1--23:??",
month = jul,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1805950.1805953",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Jul 15 18:17:23 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Quantitative generalizations of classical languages,
which assign to each word a real number instead of a
Boolean value, have applications in modeling
resource-constrained computation. We use weighted
automata (finite automata with transition weights) to
define several natural classes of quantitative
languages over finite and infinite words; in
particular, the real value of an infinite run is
computed as the maximum, limsup, liminf, limit average,
or discounted sum of the transition weights. We define
the classical decision problems of automata theory
(emptiness, universality, language inclusion, and
language equivalence) in the quantitative setting and
study their computational complexity. As the
decidability of the language-inclusion problem remains
open for some classes of weighted automata, we
introduce a notion of quantitative simulation that is
decidable and implies language inclusion. We also give
a complete characterization of the expressive power of
the various classes of weighted automata. In
particular, we show that most classes of weighted
automata cannot be determinized.",
acknowledgement = ack-nhfb,
articleno = "23",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "expressiveness; Model checking; quantitative
verification; weighted automata",
}
@Article{Creignou:2010:NBC,
author = "Nadia Creignou and Henning Schnoor and Ilka Schnoor",
title = "Nonuniform {Boolean} constraint satisfaction problems
with cardinality constraint",
journal = j-TOCL,
volume = "11",
number = "4",
pages = "24:1--24:??",
month = jul,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1805950.1805954",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Jul 15 18:17:23 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study the computational complexity of Boolean
constraint satisfaction problems with cardinality
constraint. A Galois connection between clones and
coclones has received a lot of attention in the context
of complexity considerations for constraint
satisfaction problems. This connection does not seem to
help when considering constraint satisfaction problems
that support in addition a cardinality constraint. We
prove that a similar Galois connection, involving a
weaker closure operator and partial polymorphisms, can
be applied to such problems. Thus, we establish
dichotomies for the decision as well as for the
counting problems in Schaefer's framework.",
acknowledgement = ack-nhfb,
articleno = "24",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Computational complexity; constraint satisfaction",
}
@Article{Dezani-Ciancaglini:2010:IIT,
author = "Mariangiola Dezani-Ciancaglini and Roberto {Di Cosmo}
and Elio Giovannetti and Makoto Tatsuta",
title = "On isomorphisms of intersection types",
journal = j-TOCL,
volume = "11",
number = "4",
pages = "25:1--25:??",
month = jul,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1805950.1805955",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Jul 15 18:17:23 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The study of type isomorphisms for different
$\lambda$-calculi started over twenty years ago, and a
very wide body of knowledge has been established, both
in terms of results and in terms of techniques. A
notable missing piece of the puzzle was the
characterization of type isomorphisms in the presence
of intersection types. While, at first thought, this
may seem to be a simple exercise, it turns out that not
only finding the right characterization is not simple,
but that the very notion of isomorphism in intersection
types is an unexpectedly original element in the
previously known landscape, breaking most of the known
properties of isomorphisms of the typed
$\lambda$-calculus. In particular, isomorphism is not a
congruence and types that are equal in the standard
models of intersection types may be nonisomorphic.",
acknowledgement = ack-nhfb,
articleno = "25",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "intersection types; lambda calculus; Type
isomorphism",
}
@Article{Hofmann:2010:PPP,
author = "Martin Hofmann and Ulrich Sch{\"o}pp",
title = "Pure pointer programs with iteration",
journal = j-TOCL,
volume = "11",
number = "4",
pages = "26:1--26:??",
month = jul,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1805950.1805956",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Jul 15 18:17:23 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Many logspace algorithms are naturally described as
programs that operate on a structured input (e.g., a
graph), that store in memory only a constant number of
pointers (e.g., to graph nodes) and that do not use
pointer arithmetic. Such ``pure pointer algorithms''
thus are a useful abstraction for studying the nature
of logspace-computation.\par
In this article, we introduce a formal class purple of
pure pointer programs and study them on locally ordered
graphs. Existing classes of pointer algorithms, such as
Jumping Automata on Graphs (jags) or Deterministic
Transitive Closure (dtc) logic, often exclude simple
programs. purple subsumes these classes and allows for
a natural representation of many graph algorithms that
access the input graph using a constant number of pure
pointers. It does so by providing a primitive for
iterating an algorithm over all nodes of the input
graph in an unspecified order.\par
Since pointers are given as an abstract data type
rather than as binary digits we expect that
logarithmic-size worktapes cannot be encoded using
pointers as is done, for example, in totally ordered
dtc-logic. We show that this is indeed the case by
proving that the property ``the number of nodes is a
power of two,'' which is in logspace, is not
representable in purple.",
acknowledgement = ack-nhfb,
articleno = "26",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "deterministic transitive closure logic; iteration in
unspecified order; logarithmic space; pebble
automation; Pointer program",
}
@Article{Horbach:2010:SFD,
author = "Matthias Horbach and Christoph Weidenbach",
title = "Superposition for fixed domains",
journal = j-TOCL,
volume = "11",
number = "4",
pages = "27:1--27:??",
month = jul,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1805950.1805957",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Jul 15 18:17:23 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Superposition is an established decision procedure for
a variety of first-order logic theories represented by
sets of clauses. A satisfiable theory, saturated by
superposition, implicitly defines a minimal
term-generated model for the theory. Proving universal
properties with respect to a saturated theory directly
leads to a modification of the minimal model's
term-generated domain, as new Skolem functions are
introduced. For many applications, this is not
desired.\par
Therefore, we propose the first superposition calculus
that can explicitly represent existentially quantified
variables and can thus compute with respect to a given
domain. This calculus is sound and refutationally
complete in the limit for a first-order fixed domain
semantics. For saturated Horn theories and classes of
positive formulas, we can even employ the calculus to
prove properties of the minimal model itself, going
beyond the scope of known superposition-based
approaches.",
acknowledgement = ack-nhfb,
articleno = "27",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "Automated theorem proving; fixed domain semantics;
inductionless induction; minimal model semantics; proof
by consistency; superposition",
}
@Article{Saurin:2010:TSC,
author = "Alexis Saurin",
title = "Typing streams in the {$\Lambda \mu$}-calculus",
journal = j-TOCL,
volume = "11",
number = "4",
pages = "28:1--28:??",
month = jul,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1805950.1805958",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Jul 15 18:17:23 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "$\Lambda \mu$-calculus is a B{\"o}hm-complete
extension of Parigot's $\Lambda \mu$-calculus closely
related with delimited control in functional
programming. In this article, we investigate the
meta-theory of untyped $\Lambda \mu$-calculus by
proving confluence of the calculus and characterizing
the basic observables for the Separation theorem, {\em
canonical normal forms}. Then, we define $\Lambda_s$, a
new type system for $\Lambda \mu$-calculus that
contains a special type construction for streams, and
prove that strong normalization and type preservation
hold. Thanks to the new typing discipline of
$\Lambda_s$, new computational behaviors can be
observed, which were forbidden in previous type systems
for $\Lambda \mu$-calculi. Those new typed
computational behaviors witness the stream
interpretation of $\Lambda \mu$-calculus.",
acknowledgement = ack-nhfb,
articleno = "28",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
keywords = "$\Lambda$-calculus; $\mu$-calculus; classical
$\lambda$ confluence; delimited control; B{\"o}hm
theorem; $\lambda \mu$ streams; type system",
}
@Article{Chockler:2010:EWC,
author = "Hana Chockler and Joseph Y. Halpern and Orna
Kupferman",
title = "Erratum for ``What causes a system to satisfy a
specification?''",
journal = j-TOCL,
volume = "11",
number = "4",
pages = "29:1--29:??",
month = jul,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1805950.1805959",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu Jul 15 18:17:23 MDT 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
note = "See \cite{Chockler:2008:WCS}.",
acknowledgement = ack-nhfb,
articleno = "29",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Chadha:2010:CGA,
author = "Rohit Chadha and Mahesh Viswanathan",
title = "A counterexample-guided abstraction-refinement
framework for {Markov} decision processes",
journal = j-TOCL,
volume = "12",
number = "1",
pages = "1:1--1:??",
month = oct,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1838552.1838553",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Nov 23 10:19:25 MST 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The main challenge in using abstractions effectively
is to construct a suitable abstraction for the system
being verified. One approach that tries to address this
problem is that of counterexample guided abstraction
refinement (CEGAR), wherein one starts with a coarse
abstraction of the system, and progressively refines
it, based on invalid counterexamples seen in prior
model checking runs, until either an abstraction proves
the correctness of the system or a valid counterexample
is generated. While CEGAR has been successfully used in
verifying nonprobabilistic systems automatically, CEGAR
has only recently been investigated in the context of
probabilistic systems. The main issues that need to be
tackled in order to extend the approach to
probabilistic systems is a suitable notion of
``counterexample'', algorithms to generate
counterexamples, check their validity, and then
automatically refine an abstraction based on an invalid
counterexample.",
acknowledgement = ack-nhfb,
articleno = "1",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Legay:2010:ORM,
author = "Axel Legay and Pierre Wolper",
title = "On {(Omega-)regular} model checking",
journal = j-TOCL,
volume = "12",
number = "1",
pages = "2:1--2:??",
month = oct,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1838552.1838554",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Nov 23 10:19:25 MST 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Checking infinite-state systems is frequently done by
encoding infinite sets of states as regular languages.
Computing such a regular representation of, say, the
set of reachable states of a system requires
acceleration techniques that can finitely compute the
effect of an unbounded number of transitions. Among the
acceleration techniques that have been proposed, one
finds both specific and generic techniques. Specific
techniques exploit the particular type of system being
analyzed, for example, a system manipulating queues or
integers, whereas generic techniques only assume that
the transition relation is represented by a
finite-state transducer, which has to be iterated. In
this article, we investigate the possibility of using
generic techniques in cases where only specific
techniques have been exploited so far.",
acknowledgement = ack-nhfb,
articleno = "2",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Gottlob:2010:MDF,
author = "Georg Gottlob and Reinhard Pichler and Fang Wei",
title = "Monadic datalog over finite structures of bounded
treewidth",
journal = j-TOCL,
volume = "12",
number = "1",
pages = "3:1--3:??",
month = oct,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1838552.1838555",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Nov 23 10:19:25 MST 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Bounded treewidth and monadic second-order (MSO) logic
have proved to be key concepts in establishing
fixed-parameter tractability results. Indeed, by
Courcelle's Theorem we know that any property of finite
structures, which is expressible by an MSO sentence,
can be decided in linear time (data complexity) if the
structures have bounded treewidth. In principle,
Courcelle's Theorem can be applied directly to
construct concrete algorithms by transforming the MSO
evaluation problem into a tree language recognition
problem. The latter can then be solved via a finite
tree automaton (FTA). However, this approach has turned
out to be problematical, since even relatively simple
MSO formulae may lead to a ``state explosion'' of the
FTA.",
acknowledgement = ack-nhfb,
articleno = "3",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Galesi:2010:OSD,
author = "Nicola Galesi and Massimo Lauria",
title = "Optimality of size-degree tradeoffs for polynomial
calculus",
journal = j-TOCL,
volume = "12",
number = "1",
pages = "4:1--4:??",
month = oct,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1838552.1838556",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Nov 23 10:19:25 MST 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "There are methods to turn short refutations in
polynomial calculus (Pc) and polynomial calculus with
resolution (Pcr) into refutations of low degree. Bonet
and Galesi [1999, 2003] asked if such size-degree
tradeoffs for Pc [Clegg et al. 1996; Impagliazzo et al.
1999] and Pcr [Alekhnovich et al. 2004] are optimal. We
answer this question by showing a polynomial encoding
of the graph ordering principle on m variables which
requires Pc and Pcr refutations of degree
$\Omega(\sqrt{m})$. Tradeoff optimality follows from
our result and from the short refutations of the graph
ordering principle in Bonet and Galesi [1999, 2001]. We
then introduce the algebraic proof system Pcrk which
combines together polynomial calculus and k-DNF
resolution (Resk).",
acknowledgement = ack-nhfb,
articleno = "4",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bistarelli:2010:UMQ,
author = "Stefano Bistarelli and Ugo Montanari and Francesca
Rossi and Francesco Santini",
title = "Unicast and multicast {QoS} routing with
soft-constraint logic programming",
journal = j-TOCL,
volume = "12",
number = "1",
pages = "5:1--5:??",
month = oct,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1838552.1838557",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Nov 23 10:19:25 MST 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present a formal model to represent and solve the
unicast/multicast routing problem in networks with
quality-of-service (QoS) requirements. To attain this,
first we translate the network adapting it to a
weighted graph (unicast) or and-or graph (multicast),
where the weight on a connector corresponds to the
multidimensional cost of sending a packet on the
related network link: each component of the weights
vector represents a different QoS metric value (e.g.,
bandwidth). The second step consists in writing this
graph as a program in soft-constraint logic programming
(SCLP): the engine of this framework is then able to
find the best paths\slash trees by optimizing their
costs and solving the constraints imposed on them
(e.g., delay $\leq 40$ ms), thus finding a solution to
QoS routing problems. C-semiring structures are a
convenient tool to model QoS metrics. At last, we
provide an implementation of the framework over
scale-free networks and we suggest how the performance
can be improved. The article highlights the
expressivity of SCLP.",
acknowledgement = ack-nhfb,
articleno = "5",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Billington:2010:ITD,
author = "David Billington and Grigoris Antoniou and Guido
Governatori and Michael Maher",
title = "An inclusion theorem for defeasible logics",
journal = j-TOCL,
volume = "12",
number = "1",
pages = "6:1--6:??",
month = oct,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1838552.1838558",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Nov 23 10:19:25 MST 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Defeasible reasoning is a computationally simple
nonmonotonic reasoning approach that has attracted
significant theoretical and practical attention. It
comprises a family of logics that capture different
intuitions, among them ambiguity propagation versus
ambiguity blocking, and the adoption or rejection of
team defeat. This article provides a compact
presentation of the defeasible logic variants, and
derives an inclusion theorem which shows that different
notions of provability in defeasible logic form a chain
of levels of proof.",
acknowledgement = ack-nhfb,
articleno = "6",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Cimatti:2010:EGC,
author = "Alessandro Cimatti and Alberto Griggio and Roberto
Sebastiani",
title = "Efficient generation of {Craig} interpolants in
satisfiability modulo theories",
journal = j-TOCL,
volume = "12",
number = "1",
pages = "7:1--7:??",
month = oct,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1838552.1838559",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Nov 23 10:19:25 MST 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The problem of computing Craig interpolants has
recently received a lot of interest. In this article,
we address the problem of efficient generation of
interpolants for some important fragments of
first-order logic, which are amenable for effective
decision procedures, called satisfiability modulo
theory (SMT) solvers. We make the following
contributions. First, we provide interpolation
procedures for several basic theories of interest: the
theories of linear arithmetic over the rationals,
difference logic over rationals and integers, and UTVPI
over rationals and integers. Second, we define a novel
approach to interpolate combinations of theories that
applies to the delayed theory combination approach.
Efficiency is ensured by the fact that the proposed
interpolation algorithms extend state-of-the-art
algorithms for satisfiability modulo theories.",
acknowledgement = ack-nhfb,
articleno = "7",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Furia:2010:TSC,
author = "Carlo A. Furia and Matteo Rossi",
title = "A theory of sampling for continuous-time metric
temporal logic",
journal = j-TOCL,
volume = "12",
number = "1",
pages = "8:1--8:??",
month = oct,
year = "2010",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1838552.1838560",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Nov 23 10:19:25 MST 2010",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "This article revisits the classical notion of sampling
in the setting of real-time temporal logics for the
modeling and analysis of systems. The relationship
between the satisfiability of metric temporal logic
(MTL) formulas over continuous-time models and over
discrete-time models is studied. It is shown to what
extent discrete-time sequences obtained by sampling
continuous-time signals capture the semantics of MTL
formulas over the two time domains.",
acknowledgement = ack-nhfb,
articleno = "8",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Gurevich:2011:LIP,
author = "Yuri Gurevich and Itay Neeman",
title = "Logic of infons: {The} propositional case",
journal = j-TOCL,
volume = "12",
number = "2",
pages = "9:1--9:??",
month = jan,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1877714.1877715",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jan 26 14:01:49 MST 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Infons are statements viewed as containers of
information (rather then representations of truth
values). The logic of infons turns out to be a
conservative extension of logic known as constructive
or intuitionistic. Distributed Knowledge Authorization
Language uses additional unary connectives ``p said''
and ``p implied'' where p ranges over principals. Here
we investigate infon logic and a narrow but useful
primal fragment of it. In both cases, we develop model
theory and analyze the derivability problem: Does the
given query follow from the given hypotheses? Our more
involved technical results are on primal infon logic.
We construct an algorithm for the multiple derivability
problem: Which of the given queries follow from the
given hypotheses? Given a bound on the quotation depth
of the hypotheses, the algorithm runs in linear time.",
acknowledgement = ack-nhfb,
articleno = "9",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Lazic:2011:SAA,
author = "Ranko Lazi{\'c}",
title = "Safety alternating automata on data words",
journal = j-TOCL,
volume = "12",
number = "2",
pages = "10:1--10:??",
month = jan,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1877714.1877716",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jan 26 14:01:49 MST 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A data word is a sequence of pairs of a letter from a
finite alphabet and an element from an infinite set,
where the latter can only be compared for equality.
Safety one-way alternating automata with one register
on infinite data words are considered, their
nonemptiness is shown to be ExpSpace-complete, and
their inclusion decidable but not primitive recursive.
The same complexity bounds are obtained for
satisfiability and refinement, respectively, for the
safety fragment of linear temporal logic with freeze
quantification. Dropping the safety restriction, adding
past temporal operators, or adding one more register,
each causes undecidability.",
acknowledgement = ack-nhfb,
articleno = "10",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Eiter:2011:WFS,
author = "Thomas Eiter and Giovambattista Ianni and Thomas
Lukasiewicz and Roman Schindlauer",
title = "Well-founded semantics for description logic programs
in the {Semantic Web}",
journal = j-TOCL,
volume = "12",
number = "2",
pages = "11:1--11:??",
month = jan,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1877714.1877717",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jan 26 14:01:49 MST 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The realization of the Semantic Web vision, in which
computational logic has a prominent role, has
stimulated a lot of research on combining rules and
ontologies, which are formulated in different
formalisms. In particular, combining logic programming
with the Web Ontology Language (OWL), which is a
standard based on description logics, emerged as an
important issue for linking the Rules and Ontology
Layers of the Semantic Web. Nonmonotonic description
logic programs (dl-programs) were introduced for such a
combination, in which a pair (L,P) of a description
logic knowledge base L and a set of rules P with
negation as failure is given a model-based semantics
that generalizes the answer set semantics of logic
programs.",
acknowledgement = ack-nhfb,
articleno = "11",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Szeider:2011:MSO,
author = "Stefan Szeider",
title = "Monadic second order logic on graphs with local
cardinality constraints",
journal = j-TOCL,
volume = "12",
number = "2",
pages = "12:1--12:??",
month = jan,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1877714.1877718",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jan 26 14:01:49 MST 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We introduce the class of MSO-LCC problems, which are
problems of the following form. Given a graph $G$ and
for each vertex $v$ of $G$ a set $\alpha(v)$ of
non-negative integers. Is there a set $S$ of vertices
or edges of $G$ such that, (1) $S$ satisfies a fixed
property expressible in monadic second order logic, and
(2) for each vertex $v$ of $G$ the number of
vertices\slash edges in $S$ adjacent\slash incident
with $v$ belongs to the set $\alpha(v)$? We demonstrate
that several hard combinatorial problems such as
Lov{\'a}sz's General Factor Problem can be naturally
formulated as MSO-LCC problems. Our main result is the
polynomial-time tractability of MSO-LCC problems for
graphs of bounded treewidth.",
acknowledgement = ack-nhfb,
articleno = "12",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bauland:2011:TMC,
author = "Michael Bauland and Martin Mundhenk and Thomas
Schneider and Henning Schnoor and Ilka Schnoor and
Heribert Vollmer",
title = "The tractability of model checking for {LTL}: The
good, the bad, and the ugly fragments",
journal = j-TOCL,
volume = "12",
number = "2",
pages = "13:1--13:??",
month = jan,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1877714.1877719",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jan 26 14:01:49 MST 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In a seminal paper from 1985, Sistla and Clarke showed
that the model-checking problem for Linear Temporal
Logic (LTL) is either NP-complete or PSPACE-complete,
depending on the set of temporal operators used. If in
contrast, the set of propositional operators is
restricted, the complexity may decrease. This article
systematically studies the model-checking problem for
LTL formulae over restricted sets of propositional and
temporal operators. For almost all combinations of
temporal and propositional operators, we determine
whether the model-checking problem is tractable (in
PTIME) or intractable (NP-hard). We then focus on the
tractable cases, showing that they all are NL-complete
or even logspace solvable.",
acknowledgement = ack-nhfb,
articleno = "13",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Shakarian:2011:APT,
author = "Paulo Shakarian and Austin Parker and Gerardo Simari
and Venkatramana V. S. Subrahmanian",
title = "Annotated probabilistic temporal logic",
journal = j-TOCL,
volume = "12",
number = "2",
pages = "14:1--14:??",
month = jan,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1877714.1877720",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jan 26 14:01:49 MST 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The semantics of most logics of time and probability
is given via a probability distribution over threads,
where a thread is a structure specifying what will be
true at different points in time (in the future). When
assessing the probabilities of statements such as
``Event a will occur within 5 units of time of event
b,'' there are many different semantics possible, even
when assessing the truth of this statement within a
single thread. We introduce the syntax of annotated
probabilistic temporal (APT) logic programs and
axiomatically introduce the key notion of a frequency
function (for the first time) to capture different
types of intrathread reasoning, and then provide a
semantics for intrathread and interthread reasoning in
APT logic programs parameterized by such frequency
functions.",
acknowledgement = ack-nhfb,
articleno = "14",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Urban:2011:MML,
author = "Christian Urban and James Cheney and Stefan
Berghofer",
title = "Mechanizing the metatheory of {LF}",
journal = j-TOCL,
volume = "12",
number = "2",
pages = "15:1--15:??",
month = jan,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1877714.1877721",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jan 26 14:01:49 MST 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "LF is a dependent type theory in which many other
formal systems can be conveniently embedded. However,
correct use of LF relies on nontrivial metatheoretic
developments such as proofs of correctness of decision
procedures for LF's judgments. Although detailed
informal proofs of these properties have been
published, they have not been formally verified in a
theorem prover. We have formalized these properties
within Isabelle/HOL using the Nominal Datatype Package,
closely following a recent article by Harper and
Pfenning. In the process, we identified and resolved a
gap in one of the proofs and a small number of minor
lacunae in others.",
acknowledgement = ack-nhfb,
articleno = "15",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Blass:2011:PQB,
author = "Andreas Blass and Yuri Gurevich",
title = "Persistent queries in the behavioral theory of
algorithms",
journal = j-TOCL,
volume = "12",
number = "2",
pages = "16:1--16:??",
month = jan,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1877714.1877722",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jan 26 14:01:49 MST 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We propose an extension of the behavioral theory of
interactive sequential algorithms to deal with the
following situation. A query is issued during a certain
step, but the step ends before any reply is received.
Later, a reply arrives, and later yet the algorithm
makes use of this reply. By a persistent query, we mean
a query for which a late reply might be used. Our
proposal involves issuing, along with a persistent
query, a location where a late reply is to be stored.
After presenting our proposal in general terms, we
discuss the modifications that it requires in the
existing axiomatics of interactive sequential
algorithms and in the existing syntax and semantics of
abstract state machines.",
acknowledgement = ack-nhfb,
articleno = "16",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Analyti:2011:MPF,
author = "Anastasia Analyti and Grigoris Antoniou and Carlos
Viegas Damasio",
title = "{MWeb}: a principled framework for modular {Web} rule
bases and its semantics",
journal = j-TOCL,
volume = "12",
number = "2",
pages = "17:1--17:??",
month = jan,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1877714.1877723",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Wed Jan 26 14:01:49 MST 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present a principled framework for modular Web rule
bases, called MWeb. According to this framework, each
predicate defined in a rule base is characterized by
its defining reasoning mode, scope, and exporting rule
base list. Each predicate used in a rule base is
characterized by its requesting reasoning mode and
importing rule base list. For legal MWeb modular rule
bases $S$, the MWebAS and MWebWFS semantics of each
rule base $s \in S$ with respect to $S$ are defined
model-theoretically. These semantics extend the answer
set semantics (AS) and the well-founded semantics with
explicit negation (WFSX) on ELPs, respectively, keeping
all of their semantical and computational
characteristics.",
acknowledgement = ack-nhfb,
articleno = "17",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Nielson:2011:MAC,
author = "Flemming Nielson and Sebastian Nanz and Hanne Riis
Nielson",
title = "Modal abstractions of concurrent behavior",
journal = j-TOCL,
volume = "12",
number = "3",
pages = "18:1--18:??",
month = may,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1929954.1929955",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu May 12 18:02:30 MDT 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present an effective algorithm for the automatic
construction of finite modal transition systems as
abstractions of potentially infinite concurrent
processes. Modal transition systems are recognized as
valuable abstractions for model checking because they
allow for the validation as well as refutation of
safety and liveness properties. However, the
algorithmic construction of finite abstractions from
potentially infinite concurrent processes is a missing
link that prevents their more widespread usage for
model checking of concurrent systems. Our algorithm is
a worklist algorithm using concepts from abstract
interpretation and operating upon mappings from sets to
intervals in order to express simultaneous over- and
underapproximations of the multisets of process actions
available in a particular state.",
acknowledgement = ack-nhfb,
articleno = "18",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Jurdzinski:2011:AAD,
author = "Marcin Jurdzi{\'n}ski and Ranko Lazi{\'c}",
title = "Alternating automata on data trees and {XPath}
satisfiability",
journal = j-TOCL,
volume = "12",
number = "3",
pages = "19:1--19:??",
month = may,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1929954.1929956",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu May 12 18:02:30 MDT 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A data tree is an unranked ordered tree whose every
node is labeled by a letter from a finite alphabet and
an element (``datum'') from an infinite set, where the
latter can only be compared for equality. The article
considers alternating automata on data trees that can
move downward and rightward, and have one register for
storing data. The main results are that nonemptiness
over finite data trees is decidable but not primitive
recursive, and that nonemptiness of safety automata is
decidable but not elementary. The proofs use
nondeterministic tree automata with faulty counters.
Allowing upward moves, leftward moves, or two
registers, each causes undecidability.",
acknowledgement = ack-nhfb,
articleno = "19",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{DeBruijn:2011:ENL,
author = "Jos {De Bruijn} and Thomas Eiter and Axel Polleres and
Hans Tompits",
title = "Embedding nonground logic programs into autoepistemic
logic for knowledge-base combination",
journal = j-TOCL,
volume = "12",
number = "3",
pages = "20:1--20:??",
month = may,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1929954.1929957",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu May 12 18:02:30 MDT 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In the context of the Semantic Web, several approaches
for combining ontologies, given in terms of theories of
classical first-order logic and rule bases, have been
proposed. They either cast rules into classical logic
or limit the interaction between rules and ontologies.
Autoepistemic logic (AEL) is an attractive formalism
which allows overcoming these limitations by serving as
a uniform host language to embed ontologies and
nonmonotonic logic programs into it. For the latter, so
far only the propositional setting has been considered.
In this article, we present three embeddings of normal
and three embeddings of disjunctive nonground logic
programs under the stable model semantics into
first-order AEL.",
acknowledgement = ack-nhfb,
articleno = "20",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bergstra:2011:PA,
author = "Jan A. Bergstra and Alban Ponse",
title = "Proposition algebra",
journal = j-TOCL,
volume = "12",
number = "3",
pages = "21:1--21:??",
month = may,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1929954.1929958",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu May 12 18:02:30 MDT 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Sequential propositional logic deviates from
conventional propositional logic by taking into account
that during the sequential evaluation of a
propositional statement, atomic propositions may yield
different Boolean values at repeated occurrences. We
introduce ``free valuations'' to capture this dynamics
of a propositional statement's environment. The
resulting logic is phrased as an equationally specified
algebra rather than in the form of proof rules, and is
named ``proposition algebra.'' It is strictly more
general than Boolean algebra to the extent that the
classical connectives fail to be expressively complete
in the sequential case. The four axioms for free
valuation congruence are then combined with other
axioms in order define a few more valuation congruences
that gradually identify more propositional statements,
up to static valuation congruence (which is the setting
of conventional propositional logic).",
acknowledgement = ack-nhfb,
articleno = "21",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Santo:2011:CMS,
author = "Jos{\'e} Esp{\'\i}rito Santo and Lu{\'\i}s Pinto",
title = "A calculus of multiary sequent terms",
journal = j-TOCL,
volume = "12",
number = "3",
pages = "22:1--22:??",
month = may,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1929954.1929959",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Thu May 12 18:02:30 MDT 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Multiary sequent terms were originally introduced as a
tool for proving termination of permutative conversions
in cut-free sequent calculus. This work develops the
language of multiary sequent terms into a term calculus
for the computational (Curry-Howard) interpretation of
a fragment of sequent calculus with cuts and
cut-elimination rules. The system, called generalized
multiary $\lambda$-calculus, is a rich extension of the
$\lambda$-calculus where the computational content of
the sequent calculus format is explained through an
enlarged form of the application constructor. Such
constructor exhibits the features of multiarity (the
ability to form lists of arguments) and generality (the
ability to prescribe a kind of continuation).",
acknowledgement = ack-nhfb,
articleno = "22",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Burger:2011:SIS,
author = "Lutz Stra{\ss} Burger and Alessio Guglielmi",
title = "A system of interaction and structure {IV}: The
exponentials and decomposition",
journal = j-TOCL,
volume = "12",
number = "4",
pages = "23:1--23:??",
month = jul,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1970398.1970399",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Jul 19 16:34:58 MDT 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study a system, called NEL, which is the mixed
commutative/noncommutative linear logic BV augmented
with linear logic's exponentials. Equivalently, NEL is
MELL augmented with the noncommutative self-dual
connective seq. In this article, we show a basic
compositionality property of NEL, which we call
decomposition. This result leads to a cut-elimination
theorem, which is proved in the next article of this
series. To control the induction measure for the
theorem, we rely on a novel technique that extracts
from NEL proofs the structure of exponentials, into
what we call !?-Flow-Graphs.",
acknowledgement = ack-nhfb,
articleno = "23",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bulatov:2011:CCC,
author = "Andrei A. Bulatov",
title = "Complexity of conservative constraint satisfaction
problems",
journal = j-TOCL,
volume = "12",
number = "4",
pages = "24:1--24:??",
month = jul,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1970398.1970400",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Jul 19 16:34:58 MDT 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In a constraint satisfaction problem (CSP), the aim is
to find an assignment of values to a given set of
variables, subject to specified constraints. The CSP is
known to be NP-complete in general. However, certain
restrictions on the form of the allowed constraints can
lead to problems solvable in polynomial time. Such
restrictions are usually imposed by specifying a
constraint language, that is, a set of relations that
are allowed to be used as constraints. A principal
research direction aims to distinguish those constraint
languages that give rise to tractable CSPs from those
that do not. We achieve this goal for the important
version of the CSP, in which the set of values for each
individual variable can be restricted arbitrarily.",
acknowledgement = ack-nhfb,
articleno = "24",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Ferraris:2011:LPP,
author = "Paolo Ferraris",
title = "Logic programs with propositional connectives and
aggregates",
journal = j-TOCL,
volume = "12",
number = "4",
pages = "25:1--25:??",
month = jul,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1970398.1970401",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Jul 19 16:34:58 MDT 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Answer set programming (ASP) is a logic programming
paradigm that can be used to solve complex
combinatorial search problems. Aggregates are an ASP
construct that plays an important role in many
applications. Defining a satisfactory semantics of
aggregates turned out to be a difficult problem, and in
this article we propose a new approach, based on an
analogy between aggregates and propositional
connectives. First we extend the definition of an
answer set/stable model to cover arbitrary
propositional theories; then we define aggregates on
top of them both as primitive constructs and as
abbreviations for formulas.",
acknowledgement = ack-nhfb,
articleno = "25",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Gascon:2011:UMC,
author = "Adri{\`a} Gasc{\'o}n and Guillem Godoy and Manfred
Schmidt-Schauss",
title = "Unification and matching on compressed terms",
journal = j-TOCL,
volume = "12",
number = "4",
pages = "26:1--26:??",
month = jul,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1970398.1970402",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Jul 19 16:34:58 MDT 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Term unification plays an important role in many areas
of computer science, especially in those related to
logic. The universal mechanism of grammar-based
compression for terms, in particular the so-called
singleton tree grammars (STGAs), have recently drawn
considerable attention. Using STGs, terms of
exponential size and height can be represented in
linear space. Furthermore, the term representation by
directed acyclic graphs (dags) can be efficiently
simulated. The present article is the result of an
investigation on term unification and matching when the
terms given as input are represented using different
compression mechanisms for terms such as dags and
singleton tree grammars.",
acknowledgement = ack-nhfb,
articleno = "26",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bojanczyk:2011:TVL,
author = "Miko{\l}aj Boja{\'n}czyk and Claire David and Anca
Muscholl and Thomas Schwentick and Luc Segoufin",
title = "Two-variable logic on data words",
journal = j-TOCL,
volume = "12",
number = "4",
pages = "27:1--27:??",
month = jul,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1970398.1970403",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Jul 19 16:34:58 MDT 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In a data word each position carries a label from a
finite alphabet and a data value from some infinite
domain. This model has been already considered in the
realm of semistructured data, timed automata, and
extended temporal logics. This article shows that
satisfiability for the two-variable fragment
FO2($\sim$, $<$, $+1$) of first-order logic with data
equality test $\sim$ is decidable over finite and
infinite data words. Here $+1$ and $<$ are the usual
successor and order predicates, respectively. The
satisfiability problem is shown to be at least as hard
as reachability in Petri nets.",
acknowledgement = ack-nhfb,
articleno = "27",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Chatterjee:2011:QCP,
author = "Krishnendu Chatterjee and Luca {De Alfaro} and Thomas
A. Henzinger",
title = "Qualitative concurrent parity games",
journal = j-TOCL,
volume = "12",
number = "4",
pages = "28:1--28:??",
month = jul,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1970398.1970404",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Jul 19 16:34:58 MDT 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We consider two-player games played on a finite state
space for an infinite number of rounds. The games are
concurrent: in each round, the two players (player 1
and player 2) choose their moves independently and
simultaneously; the current state and the two moves
determine the successor state. We consider
$\omega$-regular winning conditions specified as parity
objectives. Both players are allowed to use
randomization when choosing their moves. We study the
computation of the limit-winning set of states,
consisting of the states where the sup-inf value of the
game for player 1 is 1: in other words, a state is
limit-winning if player 1 can ensure a probability of
winning arbitrarily close to 1.",
acknowledgement = ack-nhfb,
articleno = "28",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Khan:2011:LIS,
author = "Md. Aquil Khan and Mohua Banerjee",
title = "Logics for information systems and their dynamic
extensions",
journal = j-TOCL,
volume = "12",
number = "4",
pages = "29:1--29:??",
month = jul,
year = "2011",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/1970398.1970405",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
bibdate = "Tue Jul 19 16:34:58 MDT 2011",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The article proposes logics for information systems,
which provide information about a set of objects
regarding a set of attributes. Both ``complete'' and
``incomplete'' information systems are dealt with. The
language of these logics contains modal operators, and
constants corresponding to attributes and attribute
values. Sound and complete deductive systems for these
logics are presented, and the problem of decidability
is addressed. Furthermore, notions of information and
information update are defined, and dynamic extensions
of the above logics are presented to accommodate these
notions. A set of reduction axioms enables us to obtain
a complete axiomatization of the dynamic logics.",
acknowledgement = ack-nhfb,
articleno = "29",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Gurfinkel:2012:RVB,
author = "Arie Gurfinkel and Marsha Chechik",
title = "Robust Vacuity for Branching Temporal Logic",
journal = j-TOCL,
volume = "13",
number = "1",
pages = "1:1--1:??",
month = jan,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2071368.2071369",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Jan 26 16:08:06 MST 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "There is a growing interest in techniques for
detecting whether a logic specification is satisfied
too easily, or vacuously. For example, the
specification ``every request is eventually followed by
an acknowledgment'' is satisfied vacuously by a system
that never generates any requests. Vacuous satisfaction
misleads users of model-checking into thinking that a
system is correct. It is a serious problem in practice.
There are several existing definitions of vacuity.
Originally, Beer et al. [1997] formalized vacuity as
insensitivity to syntactic perturbation (syntactic
vacuity). This formulation captures the intuition of
``vacuity'' when applied to a single occurrence of a
subformula. Armoni et al.",
acknowledgement = ack-nhfb,
articleno = "1",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Baelde:2012:LGF,
author = "David Baelde",
title = "Least and Greatest Fixed Points in Linear Logic",
journal = j-TOCL,
volume = "13",
number = "1",
pages = "2:1--2:??",
month = jan,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2071368.2071370",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Jan 26 16:08:06 MST 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The first-order theory of MALL (multiplicative,
additive linear logic) over only equalities is a
well-structured but weak logic since it cannot capture
unbounded (infinite) behavior. Instead of accounting
for unbounded behavior via the addition of the
exponentials (! and ?) , we add least and greatest
fixed point operators. The resulting logic, which we
call $\mu$MALL, satisfies two fundamental proof
theoretic properties: we establish weak normalization
for it, and we design a focused proof system that we
prove complete with respect to the initial system. That
second result provides a strong normal form for
cut-free proof structures that can be used, for
example, to help automate proof search.",
acknowledgement = ack-nhfb,
articleno = "2",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{vandenBerg:2012:TSM,
author = "Benno van den Berg and Richard Garner",
title = "Topological and Simplicial Models of Identity Types",
journal = j-TOCL,
volume = "13",
number = "1",
pages = "3:1--3:??",
month = jan,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2071368.2071371",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Jan 26 16:08:06 MST 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In this paper we construct new categorical models for
the identity types of Martin-L{\``o}f type theory, in
the categories Top of topological spaces and SSet of
simplicial sets. We do so building on earlier work of
Awodey and Warren [2009], which has suggested that a
suitable environment for the interpretation of identity
types should be a category equipped with a weak
factorization system in the sense of
Bousfield--Quillen. It turns out that this is not quite
enough for a sound model, due to some subtle coherence
issues concerned with stability under substitution; and
so our first task is to introduce a slightly richer
structure, which we call a homotopy-theoretic model of
identity types, and to prove that this is sufficient
for a sound interpretation.",
acknowledgement = ack-nhfb,
articleno = "3",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Gelade:2012:SCI,
author = "Wouter Gelade and Frank Neven",
title = "Succinctness of the Complement and Intersection of
Regular Expressions",
journal = j-TOCL,
volume = "13",
number = "1",
pages = "4:1--4:??",
month = jan,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2071368.2071372",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Jan 26 16:08:06 MST 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study the succinctness of the complement and
intersection of regular expressions. In particular, we
show that when constructing a regular expression
defining the complement of a given regular expression,
a double exponential size increase cannot be avoided.
Similarly, when constructing a regular expression
defining the intersection of a fixed and an arbitrary
number of regular expressions, an exponential and
double exponential size increase, respectively, cannot
be avoided. All mentioned lower bounds improve the
existing ones by one exponential and are tight in the
sense that the target expression can be constructed in
the corresponding time class, that is, exponential or
double exponential time.",
acknowledgement = ack-nhfb,
articleno = "4",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Madelaine:2012:CPF,
author = "Florent Madelaine and Barnaby Martin",
title = "The Complexity of Positive First-Order Logic without
Equality",
journal = j-TOCL,
volume = "13",
number = "1",
pages = "5:1--5:??",
month = jan,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2071368.2071373",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Jan 26 16:08:06 MST 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study the complexity of evaluating positive
equality-free sentences of first-order (FO) logic over
a fixed, finite structure B. This may be seen as a
natural generalisation of the nonuniform quantified
constraint satisfaction problem QCSP(B). We introduce
surjective hyper-endomorphisms and use them in proving
a Galois connection that characterizes definability in
positive equality-free FO. Through an algebraic method,
we derive a complete complexity classification for our
problems as B ranges over structures of size at most
three. Specifically, each problem either is in L, is
NP-complete, is co-NP-complete, or is
Pspace-complete.",
acknowledgement = ack-nhfb,
articleno = "5",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{DiGiusto:2012:EPM,
author = "Cinzia {Di Giusto} and Maurizio Gabbrielli and Maria
Chiara Meo",
title = "On the Expressive Power of Multiple Heads in {CHR}",
journal = j-TOCL,
volume = "13",
number = "1",
pages = "6:1--6:??",
month = jan,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2071368.2071374",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Jan 26 16:08:06 MST 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Constraint Handling Rules (CHR) is a committed-choice
declarative language that has been originally designed
for writing constraint solvers and is nowadays a
general purpose language. CHR programs consist of
multiheaded guarded rules which allow to rewrite
constraints into simpler ones until a solved form is
reached. Many empirical evidences suggest that multiple
heads augment the expressive power of the language,
however no formal result in this direction has been
proved, so far. In the first part of this article we
analyze the Turing completeness of CHR with respect to
the underlying constraint theory. We prove that if the
constraint theory is powerful enough then restricting
to single head rules does not affect the Turing
completeness of the language.",
acknowledgement = ack-nhfb,
articleno = "6",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Ghafari:2012:RPP,
author = "Naghmeh Ghafari and Arie Gurfinkel and Nils Klarlund
and Richard Trefler",
title = "Reachability Problems in Piecewise {FIFO} Systems",
journal = j-TOCL,
volume = "13",
number = "1",
pages = "7:1--7:??",
month = jan,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2071368.2071375",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Jan 26 16:08:06 MST 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Systems consisting of several finite components that
communicate via unbounded perfect FIFO channels (i.e.,
FIFO systems) arise naturally in modeling distributed
systems. Despite well-known difficulties in analyzing
such systems, they are of significant interest as they
can describe a wide range of communication protocols.
In this article, we study the problem of computing the
set of reachable states of a FIFO system composed of
piecewise components. This problem is closely related
to calculating the set of all possible channel
contents, that is, the limit language, for each control
location. We present an algorithm for calculating the
limit language of a system with a single communication
channel.",
acknowledgement = ack-nhfb,
articleno = "7",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Keiren:2012:SAB,
author = "Jeroen J. A. Keiren and Michel A. Reniers and Tim A.
C. Willemse",
title = "Structural Analysis of {Boolean} Equation Systems",
journal = j-TOCL,
volume = "13",
number = "1",
pages = "8:1--8:??",
month = jan,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2071368.2071376",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Jan 26 16:08:06 MST 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We analyze the problem of solving Boolean equation
systems through the use of structure graphs. The latter
are obtained through an elegant set of Plotkin-style
deduction rules. Our main contribution is that we show
that equation systems with bisimilar structure graphs
have the same solution. We show that our work
conservatively extends earlier work, conducted by
Keiren and Willemse, in which dependency graphs were
used to analyze a subclass of Boolean equation systems,
viz., equation systems in standard recursive form.",
acknowledgement = ack-nhfb,
articleno = "8",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Nguyen:2012:CPD,
author = "Phuong Nguyen and Stephen Cook",
title = "The Complexity of Proving the {Discrete Jordan Curve
Theorem}",
journal = j-TOCL,
volume = "13",
number = "1",
pages = "9:1--9:??",
month = jan,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2071368.2071377",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Jan 26 16:08:06 MST 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The Jordan curve theorem (JCT) states that a simple
closed curve divides the plane into exactly two
connected regions. We formalize and prove the theorem
in the context of grid graphs, under different input
settings, in theories of bounded arithmetic that
correspond to small complexity classes. The theory
V0(2) (corresponding to AC0(2)) proves that any set of
edges that form disjoint cycles divides the grid into
at least two regions. The theory V0 (corresponding to
AC0) proves that any sequence of edges that form a
simple closed curve divides the grid into exactly two
regions.",
acknowledgement = ack-nhfb,
articleno = "9",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Levy:2012:NUH,
author = "Jordi Levy and Mateu Villaret",
title = "Nominal Unification from a Higher-Order Perspective",
journal = j-TOCL,
volume = "13",
number = "2",
pages = "10:1--10:??",
month = apr,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2159531.2159532",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 19 17:50:31 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Nominal logic is an extension of first-order logic
with equality, name-binding, renaming via name-swapping
and freshness of names. Contrarily to lambda-terms, in
nominal terms, bindable names, called atoms, and
instantiable variables are considered as distinct
entities. Moreover, atoms are capturable by
instantiations, breaking a fundamental principle of the
lambda-calculus. Despite these differences, nominal
unification can be seen from a higher-order
perspective. From this view, we show that nominal
unification can be quadratically reduced to a
particular fragment of higher-order unification
problems: higher-order pattern unification. We also
prove that the translation preserves most generality of
unifiers.",
acknowledgement = ack-nhfb,
articleno = "10",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Berardi:2012:IRN,
author = "Stefano Berardi and Ugo de'Liguoro",
title = "Interactive Realizers: a New Approach to Program
Extraction from Nonconstructive Proofs",
journal = j-TOCL,
volume = "13",
number = "2",
pages = "11:1--11:??",
month = apr,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2159531.2159533",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 19 17:50:31 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We propose a realizability interpretation of a system
for quantier free arithmetic which is equivalent to the
fragment of classical arithmetic without nested
quantifiers, called here EM$_1$ -arithmetic. We
interpret classical proofs as interactive learning
strategies, namely as processes going through several
stages of knowledge and learning by interacting with
the ``nature,'' represented by the standard
interpretation of closed atomic formulas, and with each
other. We obtain in this way a program extraction
method by proof interpretation, which is faithful with
respect to proofs, in the sense that it is
compositional and that it does not need any
translation.",
acknowledgement = ack-nhfb,
articleno = "11",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Etessami:2012:MCR,
author = "Kousha Etessami and Mihalis Yannakakis",
title = "Model Checking of Recursive Probabilistic Systems",
journal = j-TOCL,
volume = "13",
number = "2",
pages = "12:1--12:??",
month = apr,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2159531.2159534",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 19 17:50:31 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Recursive Markov Chains (RMCs) are a natural abstract
model of procedural probabilistic programs and related
systems involving recursion and probability. They
succinctly define a class of denumerable Markov chains
that generalize several other stochastic models, and
they are equivalent in a precise sense to probabilistic
Pushdown Systems. In this article, we study the problem
of model checking an RMC against an $\omega$-regular
specification, given in terms of a B{\"u}chi automaton
or a Linear Temporal Logic (LTL) formula. Namely, given
an RMC A and a property, we wish to know the
probability that an execution of A satisfies the
property. We establish a number of strong upper bounds,
as well as lower bounds, both for qualitative problems
(is the probability = 1, or = 0?), and for quantitative
problems (is the probability {$>$}= p?, or, approximate
the probability to within a desired precision). The
complexity upper bounds we obtain for automata and LTL
properties are similar, although the algorithms are
different. We present algorithms for the qualitative
model checking problem that run in polynomial space in
the size | A | of the RMC and exponential time in the
size of the property (the automaton or the LTL
formula). For several classes of RMCs, including
single-exit RMCs (a class that encompasses some
well-studied stochastic models, for instance,
stochastic context-free grammars) the algorithm runs in
polynomial time in | A |. For the quantitative model
checking problem, we present algorithms that run in
polynomial space in the RMC and exponential space in
the property. For the class of linearly recursive RMCs
we can compute the exact probability in time polynomial
in the RMC and exponential in the property. For
deterministic automata specifications, all our
complexities in the specification come down by one
exponential. For lower bounds, we show that the
qualitative model checking problem, even for a fixed
RMC, is already EXPTIME-complete. On the other hand,
even for simple reachability analysis, we know from our
prior work that our PSPACE upper bounds in A can not be
improved substantially without a breakthrough on a
well-known open problem in the complexity of numerical
computation.",
acknowledgement = ack-nhfb,
articleno = "12",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Shakarian:2012:APT,
author = "Paulo Shakarian and Gerardo I. Simari and V. S.
Subrahmanian",
title = "Annotated Probabilistic Temporal Logic: Approximate
Fixpoint Implementation",
journal = j-TOCL,
volume = "13",
number = "2",
pages = "13:1--13:??",
month = apr,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2159531.2159535",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 19 17:50:31 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Annotated Probabilistic Temporal (APT) logic programs
support building applications where we wish to reason
about statements of the form ``Formula $G$ becomes true
with a probability in the range $[ L, U ]$ within (or
in exactly) $\Delta t$ time units after formula $F$
became true.'' In this paper, we present a sound, but
incomplete fixpoint operator that can be used to check
consistency and entailment in APT logic programs. We
present the first implementation of APT-logic programs
and evaluate both its compute time and convergence on a
suite of 23 ground APT-logic programs that were
automatically learned from two real-world data sets. In
both cases, the APT-logic programs contained up to
1,000 ground rules. In one data set, entailment
problems were solved on average in under 0.1 seconds
per ground rule, while in the other, it took up to 1.3
seconds per ground rule. Consistency was also checked
in a reasonable amount of time. When discussing
entailment of APT-logic formulas, convergence of the
fixpoint operator refers to $( U - L )$ being below a
certain threshold. We show that on virtually all of the
23 automatically generated APT-logic programs,
convergence was quick---often in just 2--3 iterations
of the fixpoint operator. Thus, our implementation is a
practical first step towards checking consistency and
entailment in temporal probabilistic logics without
independence or Markovian assumptions.",
acknowledgement = ack-nhfb,
articleno = "13",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Ferrari:2012:SRI,
author = "Mauro Ferrari and Camillo Fiorentini and Guido
Fiorino",
title = "Simplification Rules for Intuitionistic Propositional
Tableaux",
journal = j-TOCL,
volume = "13",
number = "2",
pages = "14:1--14:??",
month = apr,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2159531.2159536",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 19 17:50:31 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The implementation of a logic requires, besides the
definition of a calculus and a decision procedure, the
development of techniques to reduce the search space.
In this article we introduce some simplification rules
for Intuitionistic propositional logic that try to
replace a formula with an equi-satisfiable ``simpler''
one with the aim to reduce the search space. Our
results are proved via semantical techniques based on
Kripke models. We also provide an empirical evaluation
of their impact on implementations.",
acknowledgement = ack-nhfb,
articleno = "14",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Danicic:2012:CDD,
author = "Sebastian Danicic and Robert M. Hierons and Michael R.
Laurence",
title = "Complexity of Data Dependence Problems for Program
Schemas with Concurrency",
journal = j-TOCL,
volume = "13",
number = "2",
pages = "15:1--15:??",
month = apr,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2159531.2159537",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 19 17:50:31 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The problem of deciding whether one point in a program
is data dependent upon another is fundamental to
program analysis and has been widely studied. In this
article we consider this problem at the abstraction
level of program schemas in which computations occur in
the Herbrand domain of terms and predicate symbols,
which represent arbitrary predicate functions, are
allowed. Given a vertex l in the flowchart of a schema
S having only equality (variable copying) assignments,
and variables v, w, we show that it is PSPACE-hard to
decide whether there exists an execution of a program
defined by S in which v holds the initial value of w at
least one occurrence of l on the path of execution,
with membership in PSPACE holding provided there is a
constant upper bound on the arity of any predicate in
S. We also consider the `dual' problem in which v is
required to hold the initial value of w at every
occurrence of l, for which the analogous results hold.
Additionally, the former problem for programs with
nondeterministic branching (in effect, free schemas) in
which assignments with functions are allowed is proved
to be polynomial-time decidable provided a constant
upper bound is placed upon the number of occurrences of
the concurrency operator in the schemas being
considered. This result is promising since many
concurrent systems have a relatively small number of
threads (concurrent processes), especially when
compared with the number of statements they have.",
acknowledgement = ack-nhfb,
articleno = "15",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Nordstrom:2012:RSP,
author = "Jakob Nordstr{\"o}m",
title = "On the Relative Strength of Pebbling and Resolution",
journal = j-TOCL,
volume = "13",
number = "2",
pages = "16:1--16:??",
month = apr,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2159531.2159538",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 19 17:50:31 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The last decade has seen a revival of interest in
pebble games in the context of proof complexity.
Pebbling has proven to be a useful tool for studying
resolution-based proof systems when comparing the
strength of different subsystems, showing bounds on
proof space, and establishing size-space trade-offs.
The typical approach has been to encode the pebble game
played on a graph as a CNF formula and then argue that
proofs of this formula must inherit (various aspects
of) the pebbling properties of the underlying graph.
Unfortunately, the reductions used here are not tight.
To simulate resolution proofs by pebblings, the full
strength of nondeterministic black-white pebbling is
needed, whereas resolution is only known to be able to
simulate deterministic black pebbling. To obtain strong
results, one therefore needs to find specific graph
families which either have essentially the same
properties for black and black-white pebbling (not at
all true in general) or which admit simulations of
black-white pebblings in resolution. This article
contributes to both these approaches. First, we design
a restricted form of black-white pebbling that can be
simulated in resolution and show that there are graph
families for which such restricted pebblings can be
asymptotically better than black pebblings. This proves
that, perhaps somewhat unexpectedly, resolution can
strictly beat black-only pebbling, and in particular
that the space lower bounds on pebbling formulas in
Ben-Sasson and Nordstr{\"o}m [2008] are tight. Second,
we present a versatile parametrized graph family with
essentially the same properties for black and
black-white pebbling, which gives sharp simultaneous
trade-offs for black and black-white pebbling for
various parameter settings. Both of our contributions
have been instrumental in obtaining the time-space
trade-off results for resolution-based proof systems in
Ben-Sasson and Nordstr{\"o}m [2011].",
acknowledgement = ack-nhfb,
articleno = "16",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Creignou:2012:CRF,
author = "Nadia Creignou and Arne Meier and Heribert Vollmer and
Michael Thomas",
title = "The Complexity of Reasoning for Fragments of
Autoepistemic Logic",
journal = j-TOCL,
volume = "13",
number = "2",
pages = "17:1--17:??",
month = apr,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2159531.2159539",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 19 17:50:31 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Autoepistemic logic extends propositional logic by the
modal operator $L$. A formula $\varphi$ that is
preceded by an $L$ is said to be ``believed.'' The
logic was introduced by Moore in 1985 for modeling an
ideally rational agent's behavior and reasoning about
his own beliefs. In this article we analyze all Boolean
fragments of autoepistemic logic with respect to the
computational complexity of the three most common
decision problems expansion existence, brave reasoning
and cautious reasoning. As a second contribution we
classify the computational complexity of checking that
a given set of formulae characterizes a stable
expansion and that of counting the number of stable
expansions of a given knowledge base. We improve the
best known $\Delta_2^p$-upper bound on the former
problem to completeness for the second level of the
Boolean hierarchy. To the best of our knowledge, this
is the first paper analyzing counting problem for
autoepistemic logic.",
acknowledgement = ack-nhfb,
articleno = "17",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Gaboardi:2012:ICP,
author = "Marco Gaboardi and Jean-Yves Marion and Simona Ronchi
Della Rocca",
title = "An Implicit Characterization of {PSPACE}",
journal = j-TOCL,
volume = "13",
number = "2",
pages = "18:1--18:??",
month = apr,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2159531.2159540",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 19 17:50:31 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present a type system for an extension of lambda
calculus with a conditional construction, named
STA$_B$, that characterizes the PSPACE class. This
system is obtained by extending STA, a type assignment
for lambda-calculus inspired by Lafont's Soft Linear
Logic and characterizing the PTIME class. We extend STA
by means of a ground type and terms for Booleans and
conditional. The key issue in the design of the type
system is to manage the contexts in the rule for
conditional in an additive way. Thanks to this rule, we
are able to program polynomial time Alternating Turing
Machines. From the well-known result APTIME = PSPACE,
it follows that STA$_B$ is complete for PSPACE.
Conversely, inspired by the simulation of Alternating
Turing machines by means of Deterministic Turing
machine, we introduce a call-by-name evaluation machine
with two memory devices in order to evaluate programs
in polynomial space. As far as we know, this is the
first characterization of PSPACE that is based on
lambda calculus and light logics.",
acknowledgement = ack-nhfb,
articleno = "18",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Gelade:2012:DCF,
author = "Wouter Gelade and Marcel Marquardt and Thomas
Schwentick",
title = "The dynamic complexity of formal languages",
journal = j-TOCL,
volume = "13",
number = "3",
pages = "19:1--19:??",
month = aug,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2287718.2287719",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 24 16:18:32 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The article investigates the power of the dynamic
complexity classes D ynFO, DynQF, and DynPROP over
string languages. The latter two classes contain
problems that can be maintained using quantifier-free
first-order updates, with and without auxiliary
functions, respectively. It is shown that the languages
maintainable in DynPROP are exactly the regular
languages, even when allowing arbitrary precomputation.
This enables lower bounds for DynPROP and separates
DynPROP from DynQF and DynFO. Further, it is shown that
any context-free language can be maintained in DynFO
and a number of specific context-free languages, for
example all Dyck-languages, are maintainable in DynQF.
Furthermore, the dynamic complexity of regular tree
languages is investigated and some results concerning
arbitrary structures are obtained: There exist
first-order definable properties which are not
maintainable in DynPROP. On the other hand, any
existential first-order property can be maintained in
DynQF when allowing precomputation.",
acknowledgement = ack-nhfb,
articleno = "19",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Dowek:2012:PNL,
author = "Gilles Dowek and Murdoch J. Gabbay",
title = "Permissive-nominal logic: First-order logic over
nominal terms and sets",
journal = j-TOCL,
volume = "13",
number = "3",
pages = "20:1--20:??",
month = aug,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2287718.2287720",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 24 16:18:32 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Permissive-Nominal Logic (PNL) is an extension of
first-order predicate logic in which term-formers can
bind names in their arguments. This allows for direct
axiomatizations with binders, such as of the
$\lambda$-binder of the lambda-calculus or the
$\forall$-binder of first-order logic. It also allows
us to finitely axiomatize arithmetic, and similarly to
axiomatize ``nominal'' datatypes-with-binding. Just
like first- and higher-order logic, equality reasoning
is not necessary to $\alpha$-rename. This gives PNL
much of the expressive power of higher-order logic, but
models and derivations of PNL are first-order in
character, and the logic seems to strike a good balance
between expressivity and simplicity.",
acknowledgement = ack-nhfb,
articleno = "20",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Baader:2012:LDL,
author = "Franz Baader and Silvio Ghilardi and Carsten Lutz",
title = "{LTL} over description logic axioms",
journal = j-TOCL,
volume = "13",
number = "3",
pages = "21:1--21:??",
month = aug,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2287718.2287721",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 24 16:18:32 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Most of the research on temporalized Description
Logics (DLs) has concentrated on the case where
temporal operators can be applied to concepts, and
sometimes additionally to TBox axioms and ABox
assertions. The aim of this article is to study
temporalized DLs where temporal operators on TBox
axioms and ABox assertions are available, but temporal
operators on concepts are not. While the main
application of existing temporalized DLs is the
representation of conceptual models that explicitly
incorporate temporal aspects, the family of DLs studied
in this article addresses applications that focus on
the temporal evolution of data and of ontologies. Our
results show that disallowing temporal operators on
concepts can significantly decrease the complexity of
reasoning. In particular, reasoning with rigid roles
(whose interpretation does not change over time) is
typically undecidable without such a syntactic
restriction, whereas our logics are decidable in
elementary time even in the presence of rigid roles. We
analyze the effects on computational complexity of
dropping rigid roles, dropping rigid concepts,
replacing temporal TBoxes with global ones, and
restricting the set of available temporal operators. In
this way, we obtain a novel family of temporalized DLs
whose complexity ranges from 2- ExpTime-complete via
NExpTime-complete to ExpTime-complete.",
acknowledgement = ack-nhfb,
articleno = "21",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{More:2012:CCG,
author = "Sara Miner More and Pavel Naumov",
title = "Calculus of cooperation and game-based reasoning about
protocol privacy",
journal = j-TOCL,
volume = "13",
number = "3",
pages = "22:1--22:??",
month = aug,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2287718.2287722",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 24 16:18:32 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The article introduces a new formal system, the
calculus of cooperation, for reasoning about coalitions
of players in a certain class of games. The calculus is
an extension of the propositional intuitionistic logic
that adds a coalition parameter to intuitionistic
implication. The system is shown to be sound and
complete with respect to a game semantics. One intended
application of the calculus of cooperation is the
verification of privacy properties in multiparty
computation protocols. The article argues that such
properties can be established by providing a set of
strategies for a non-zero-sum, perfect information game
based on the protocol. It concludes with several
examples of such verifications formalized in the
calculus of cooperation.",
acknowledgement = ack-nhfb,
articleno = "22",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Makino:2012:DII,
author = "Kazuhisa Makino and Hirotaka Ono",
title = "Deductive inference for the interiors and exteriors of
{Horn} theories",
journal = j-TOCL,
volume = "13",
number = "3",
pages = "23:1--23:??",
month = aug,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2287718.2287723",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 24 16:18:32 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In this article, we investigate deductive inference
for interiors and exteriors of Horn knowledge bases,
where interiors and exteriors were introduced by Makino
and Ibaraki [1996] to study stability properties of
knowledge bases. We present a linear time algorithm for
deduction for interiors and show that deduction is
coNP-complete for exteriors. Under model-based
representation, we show that the deduction problem for
interiors is NP-complete while the one for exteriors is
coNP-complete. As for Horn envelopes of exteriors, we
show that it is linearly solvable under model-based
representation, while it is coNP-complete under
formula-based representation. We also discuss
polynomially solvable cases for all the intractable
problems.",
acknowledgement = ack-nhfb,
articleno = "23",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Kjos-Hanssen:2012:ACE,
author = "Bj{\o}rn Kjos-Hanssen and Frank Stephan and Jason
Teutsch",
title = "Arithmetic complexity via effective names for random
sequences",
journal = j-TOCL,
volume = "13",
number = "3",
pages = "24:1--24:??",
month = aug,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2287718.2287724",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 24 16:18:32 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We investigate enumerability properties for classes of
sets which permit recursive, lexicographically
increasing approximations, or left-r.e. sets. In
addition to pinpointing the complexity of left-r.e.
Martin-L{\"o}f, computably, Schnorr, and Kurtz random
sets, weakly 1-generics and their complementary
classes, we find that there exist characterizations of
the third and fourth levels of the arithmetic hierarchy
purely in terms of these notions. More generally, there
exists an equivalence between arithmetic complexity and
existence of numberings for classes of left-r.e. sets
with shift-persistent elements. While some classes
(such as Martin-L{\"o}f randoms and Kurtz nonrandoms)
have left-r.e. numberings, there is no canonical, or
acceptable, left-r.e. numbering for any class of
left-r.e. randoms. Finally, we note some fundamental
differences between left-r.e. numberings for sets and
reals.",
acknowledgement = ack-nhfb,
articleno = "24",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bianco:2012:GCT,
author = "Alessandro Bianco and Fabio Mogavero and Aniello
Murano",
title = "Graded computation tree logic",
journal = j-TOCL,
volume = "13",
number = "3",
pages = "25:1--25:??",
month = aug,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2287718.2287725",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 24 16:18:32 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In modal logics, graded (world) modalities have been
deeply investigated as a useful framework for
generalizing standard existential and universal
modalities in such a way that they can express
statements about a given number of immediately
accessible worlds. These modalities have been recently
investigated with respect to the $\mu$ Calculus, which
have provided succinctness, without affecting the
satisfiability of the extended logic, that is, it
remains solvable in ExpTime. A natural question that
arises is how logics that allow reasoning about paths
could be affected by considering graded path
modalities. In this article, we investigate this
question in the case of the branching-time temporal
logic CTL (GCTL, for short). We prove that, although
GCTL is more expressive than CTL, the satisfiability
problem for GCTL remains solvable in ExpTime, even in
the case that the graded numbers are coded in binary.
This result is obtained by exploiting an
automata-theoretic approach, which involves a model of
alternating automata with satellites. The
satisfiability result turns out to be even more
interesting as we show that GCTL is at least
exponentially more succinct than graded $\mu$
Calculus.",
acknowledgement = ack-nhfb,
articleno = "25",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Goldblatt:2012:WSP,
author = "Robert Goldblatt and Marcel Jackson",
title = "Well-structured program equivalence is highly
undecidable",
journal = j-TOCL,
volume = "13",
number = "3",
pages = "26:1--26:??",
month = aug,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2287718.2287726",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 24 16:18:32 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We show that strict deterministic propositional
dynamic logic with intersection is highly undecidable,
solving a problem in the Stanford Encyclopedia of
Philosophy. In fact we show something quite a bit
stronger. We introduce the construction of program
equivalence, which returns the value $\top$ precisely
when two given programs are equivalent on halting
computations. We show that virtually any variant of
propositional dynamic logic has a $\Pi_1^1$-hard
validity problem if it can express even just the
equivalence of well-structured programs with the empty
program skip. We also show, in these cases, that the
set of propositional statements valid over finite
models is not recursively enumerable, so there is not
even an axiomatization for finitely valid
propositions.",
acknowledgement = ack-nhfb,
articleno = "26",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Alur:2012:AAA,
author = "Rajeev Alur and Pavol Cern{\'y} and Scott Weinstein",
title = "Algorithmic analysis of array-accessing programs",
journal = j-TOCL,
volume = "13",
number = "3",
pages = "27:1--27:??",
month = aug,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2287718.2287727",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 24 16:18:32 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "For programs whose data variables range over Boolean
or finite domains, program verification is decidable,
and this forms the basis of recent tools for software
model checking. In this article, we consider
algorithmic verification of programs that use Boolean
variables, and in addition, access a single read-only
array whose length is potentially unbounded, and whose
elements range over an unbounded data domain. We show
that the reachability problem, while undecidable in
general, is (1) Pspace-complete for programs in which
the array-accessing for-loops are not nested, (2)
decidable for a restricted class of programs with
doubly nested loops. The second result establishes
connections to automata and logics defining languages
over data words.",
acknowledgement = ack-nhfb,
articleno = "27",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Chatzikokolakis:2012:ESG,
author = "Konstantinos Chatzikokolakis and Sophia Knight and
Catuscia Palamidessi and Prakash Panangaden",
title = "Epistemic Strategies and Games on Concurrent
Processes",
journal = j-TOCL,
volume = "13",
number = "4",
pages = "28:1--28:??",
month = oct,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2362355.2362356",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Oct 23 06:11:18 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We develop a game semantics for process algebra with
two interacting agents. The purpose of our semantics is
to make manifest the role of knowledge and information
flow in the interactions between agents and to control
the information available to interacting agents. We
define games and strategies on process algebras, so
that two agents interacting according to their
strategies determine the execution of the process,
replacing the traditional scheduler. We show that
different restrictions on strategies represent
different amounts of information being available to a
scheduler. We also show that a certain class of
strategies corresponds to the syntactic schedulers of
Chatzikokolakis and Palamidessi, which were developed
to overcome problems with traditional schedulers
modelling interaction. The restrictions on these
strategies have an explicit epistemic flavour.",
acknowledgement = ack-nhfb,
articleno = "28",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Boker:2012:TCB,
author = "Udi Boker and Orna Kupferman",
title = "Translating to {Co--B{\"u}chi} Made Tight, Unified,
and Useful",
journal = j-TOCL,
volume = "13",
number = "4",
pages = "29:1--29:??",
month = oct,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2362355.2362357",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Oct 23 06:11:18 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We solve the longstanding open problems of the blow-up
involved in the translations, when possible, of a
nondeterministic B{\"u}chi word automaton (NBW) to a
nondeterministic co-B{\"u}chi word automaton (NCW) and
to a deterministic co-B{\"u}chi word automaton (DCW).
For the NBW to NCW translation, the currently known
upper bound is $2^{O(n \log n)}$ and the lower bound is
$1.5 n$. We improve the upper bound to $n 2^n$ and
describe a matching lower bound of $2^{\Omega(n)}$. For
the NBW to DCW translation, the currently known upper
bound is $2^{O(n \log n)}$. We improve it to
$2^{O(n)}$, which is asymptotically tight. Both of our
upper-bound constructions are based on a simple subset
construction, do not involve intermediate automata with
richer acceptance conditions, and can be implemented
symbolically. We continue and solve the open problems
of translating nondeterministic Streett, Rabin, Muller,
and parity word automata to NCW and to DCW. Going via
an intermediate NBW is not optimal and we describe
direct, simple, and asymptotically tight constructions,
involving a $2^{\Theta(n)}$ blow-up. The constructions
are variants of the subset construction, providing a
unified approach for translating all common classes of
automata to NCW and DCW. Beyond the theoretical
importance of the results, we point to numerous
applications of the new constructions. In particular,
they imply a simple subset-construction based
translation, when possible, of LTL to deterministic
B{\"u}chi word automata.",
acknowledgement = ack-nhfb,
articleno = "29",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Peppas:2012:MMB,
author = "Pavlos Peppas and Costas D. Koutras and Mary-Anne
Williams",
title = "Maps in Multiple Belief Change",
journal = j-TOCL,
volume = "13",
number = "4",
pages = "30:1--30:??",
month = oct,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2362355.2362358",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Oct 23 06:11:18 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Multiple Belief Change extends the classical AGM
framework for Belief Revision introduced by Alchourron,
Gardenfors, and Makinson in the early '80s. The
extended framework includes epistemic input represented
as a (possibly infinite) set of sentences, as opposed
to a single sentence assumed in the original framework.
The transition from single to multiple epistemic input
worked out well for the operation of belief revision.
The AGM postulates and the system-of-spheres model were
adequately generalized and so was the representation
result connecting the two. In the case of belief
contraction however, the transition was not as smooth.
The generalized postulates for contraction, which were
shown to correspond precisely to the generalized
partial meet model, failed to match up to the
generalized epistemic entrenchment model. The mismatch
was fixed with the addition of an extra postulate,
called the limit postulate, that relates contraction by
multiple epistemic input to a series of contractions by
single epistemic input. The new postulate however
creates problems on other fronts. First, the limit
postulate needs to be mapped into appropriate
constraints in the partial meet model. Second, via the
Levi and Harper Identities, the new postulate
translates into an extra postulate for multiple
revision, which in turn needs to be characterized in
terms of systems of spheres. Both these open problems
are addressed in this article. In addition, the limit
postulate is compared with a similar condition in the
literature, called (K*F), and is shown to be strictly
weaker than it. An interesting aspect of our results is
that they reveal a profound connection between
rationality in multiple belief change and the notion of
an elementary set of possible worlds (closely related
to the notion of an elementary class of models from
classical logic).",
acknowledgement = ack-nhfb,
articleno = "30",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Durand:2012:HDL,
author = "Arnaud Durand and Juha Kontinen",
title = "Hierarchies in Dependence Logic",
journal = j-TOCL,
volume = "13",
number = "4",
pages = "31:1--31:??",
month = oct,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2362355.2362359",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Oct 23 06:11:18 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study fragments $D( k \forall)$ and $D(k-{\rm
dep})$ of dependence logic defined either by
restricting the number $k$ of universal quantifiers or
the width of dependence atoms in formulas. We find the
sublogics of existential second-order logic
corresponding to these fragments of dependence logic.
We also show that, for any fixed signature, the
fragments $D(k \forall)$ give rise to an infinite
hierarchy with respect to expressive power. On the
other hand, for the fragments $D(k-{\rm dep})$, a
hierarchy theorem is obtained only in the case the
signature is also allowed to vary. For any fixed
signature, this question is open and is related to the
so-called Spectrum Arity Hierarchy Conjecture.",
acknowledgement = ack-nhfb,
articleno = "31",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Madalinska-Bugaj:2012:GQE,
author = "Ewa Madali{\'n}ska-Bugaj and Linh Anh Nguyen",
title = "A Generalized {QSQR} Evaluation Method for {Horn}
Knowledge Bases",
journal = j-TOCL,
volume = "13",
number = "4",
pages = "32:1--32:??",
month = oct,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2362355.2362360",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Oct 23 06:11:18 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We generalize the QSQR evaluation method to give the
first set-oriented depth-first evaluation method for
Horn knowledge bases. The resulting procedure closely
simulates SLD-resolution (to take advantages of the
goal-directed approach) and highly exploits
set-at-a-time tabling. Our generalized QSQR evaluation
procedure is sound and complete. It does not use
adornments and annotations. To deal with function
symbols, our procedure uses iterative deepening search,
which iteratively increases term-depth bound for atoms
and substitutions occurring in the computation. When
the term-depth bound is fixed, our evaluation procedure
runs in polynomial time in the size of extensional
relations.",
acknowledgement = ack-nhfb,
articleno = "32",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Schockaert:2012:FEL,
author = "Steven Schockaert and Jeroen Janssen and Dirk
Vermeir",
title = "Fuzzy Equilibrium Logic: Declarative Problem Solving
in Continuous Domains",
journal = j-TOCL,
volume = "13",
number = "4",
pages = "33:1--33:??",
month = oct,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2362355.2362361",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Oct 23 06:11:18 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In this article, we introduce fuzzy equilibrium logic
as a generalization of both Pearce equilibrium logic
and fuzzy answer set programming. The resulting
framework combines the capability of equilibrium logic
to declaratively specify search problems, with the
capability of fuzzy logics to model continuous domains.
We show that our fuzzy equilibrium logic is a proper
generalization of both Pearce equilibrium logic and
fuzzy answer set programming, and we locate the
computational complexity of the main reasoning tasks at
the second level of the polynomial hierarchy. We then
provide a reduction from the problem of finding fuzzy
equilibrium logic models to the problem of solving a
particular bilevel mixed integer program (biMIP),
allowing us to implement reasoners by reusing existing
work from the operations research community. To
illustrate the usefulness of our framework from a
theoretical perspective, we show that a well-known
characterization of strong equivalence in Pearce
equilibrium logic generalizes to our setting, yielding
a practical method to verify whether two fuzzy answer
set programs are strongly equivalent. Finally, to
illustrate its application potential, we show how fuzzy
equilibrium logic can be used to find strong Nash
equilibria, even when players have a continuum of
strategies at their disposal. As a second application
example, we show how to find abductive explanations
from Lukasiewicz logic theories.",
acknowledgement = ack-nhfb,
articleno = "33",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Figueira:2012:DDX,
author = "Diego Figueira",
title = "Decidability of Downward {XPath}",
journal = j-TOCL,
volume = "13",
number = "4",
pages = "34:1--34:??",
month = oct,
year = "2012",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2362355.2362362",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Oct 23 06:11:18 MDT 2012",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We investigate the satisfiability problem for
downward-XPath, the fragment of XPath that includes the
child and descendant axes, and tests for (in)equality
of attributes' values. We prove that this problem is
decidable, EXPTIME-complete. These bounds also hold
when path expressions allow closure under the Kleene
star operator. To obtain these results, we introduce a
Downward Data automata model (DD automata) over trees
with data, which has a decidable emptiness problem.
Satisfiability of downward-XPath can be reduced to the
emptiness problem of DD automata and hence its
decidability follows. Although downward-XPath does not
include any horizontal axis, DD automata are more
expressive and can perform some horizontal tests. Thus,
we show that the satisfiability remains in EXPTIME even
in the presence of the regular constraints expressible
by DD automata. However, the same problem in the
presence of any regular constraint is known to have a
nonprimitive recursive complexity. Finally, we give the
exact complexity of the satisfiability problem for
several fragments of downward-XPath.",
acknowledgement = ack-nhfb,
articleno = "34",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Betz:2013:LLB,
author = "Hariolf Betz and Thom Fr{\"u}hwirth",
title = "Linear-Logic Based Analysis of Constraint Handling
Rules with Disjunction",
journal = j-TOCL,
volume = "14",
number = "1",
pages = "1:1--1:??",
month = feb,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2422085.2422086",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Feb 20 16:38:47 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Constraint Handling Rules (CHR) is a declarative
rule-based programming language that has cut out its
niche over the course of the last 20 years. It
generalizes concurrent constraint logic programming to
multiple heads, thus closing the gap to multiset
transformation systems. Its popular extension CHR with
Disjunction (CHR$ \vee $ ) is a multiparadigm
declarative programming language that allows embedding
of Horn programs with SLD resolution. We analyze the
assets and the limitations of the classical declarative
semantics of CHR$ \vee $ and highlight its natural
relationship with linear-logic. We furthermore develop
two linear-logic semantics for CHR$ \vee $ that differ
in the reasoning domain for which they are
instrumental. We show their idempotence and their
soundness and completeness with respect to the
operational semantics. We show how to apply the
linear-logic semantics to decide program properties and
to reason about operational equivalence of CHR$ \vee $
programs.",
acknowledgement = ack-nhfb,
articleno = "1",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Krotzsch:2013:CHD,
author = "Markus Kr{\"o}tzsch and Sebastian Rudolph and Pascal
Hitzler",
title = "Complexities of {Horn} Description Logics",
journal = j-TOCL,
volume = "14",
number = "1",
pages = "2:1--2:??",
month = feb,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2422085.2422087",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Feb 20 16:38:47 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Description logics (DLs) have become a prominent
paradigm for representing knowledge in a variety of
application areas, partly due to their ability to
achieve a favourable balance between expressivity of
the logic and performance of reasoning. Horn
description logics are obtained, roughly speaking, by
disallowing all forms of disjunctions. They have
attracted attention since their (worst-case) data
complexities are in general lower than those of their
non-Horn counterparts, which makes them attractive for
reasoning with large sets of instance data (ABoxes). It
is therefore natural to ask whether Horn DLs also
provide advantages for schema (TBox) reasoning, that
is, whether they also feature lower combined
complexities. This article settles this question for a
variety of Horn DLs. An example of a tractable Horn
logic is the DL underlying the ontology language OWL
RL, which we characterize as the Horn fragment of the
description logic SROIQ without existential
quantifiers. If existential quantifiers are allowed,
however, many Horn DLs become intractable. We find that
Horn- ALC already has the same worst-case complexity as
ALC, that is, ExpTime, but we also identify various DLs
for which reasoning is PSpace-complete. As a side
effect, we derive simplified syntactic definitions of
Horn DLs for which we exploit suitable normal form
transformations.",
acknowledgement = ack-nhfb,
articleno = "2",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Chen:2013:CLM,
author = "Xiaoping Chen and Jianmin Ji and Fangzhen Lin",
title = "Computing Loops with at Most One External Support
Rule",
journal = j-TOCL,
volume = "14",
number = "1",
pages = "3:1--3:??",
month = feb,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2422085.2422088",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Feb 20 16:38:47 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A consequence of a logic program under answer set
semantics is one that is true for all answer sets. This
article considers using loop formulas to compute some
of these consequences in order to increase the
efficiency of answer set solvers. Since computing loop
formulas are in general intractable, we consider only
loops with either no external support or at most one
external support, as their loop formulas are either
unit or binary clauses. We show that for disjunctive
logic programs, loop formulas of loops with no external
support can be computed in polynomial time, and that an
iterative procedure using unit propagation on these
formulas and the program completion computes the
well-founded models in the case of normal logic
programs and the least fixed point of a simplification
operator used by DLV for disjunctive logic programs.
For loops with at most one external support, their loop
formulas can be computed in polynomial time for normal
logic programs, but are NP-hard for disjunctive
programs. So for normal logic programs, we have a
procedure similar to the iterative one for loops
without any external support, but for disjunctive logic
programs, we present a polynomial approximation
algorithm. All these algorithms have been implemented,
and our experiments show that for certain logic
programs, the consequences computed by our algorithms
can significantly speed up current ASP solvers cmodels,
clasp, and DLV.",
acknowledgement = ack-nhfb,
articleno = "3",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Baudet:2013:YGT,
author = "Mathieu Baudet and V{\'e}ronique Cortier and
St{\'e}phanie Delaune",
title = "{YAPA}: a Generic Tool for Computing Intruder
Knowledge",
journal = j-TOCL,
volume = "14",
number = "1",
pages = "4:1--4:??",
month = feb,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2422085.2422089",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Feb 20 16:38:47 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Reasoning about the knowledge of an attacker is a
necessary step in many formal analyses of security
protocols. In the framework of the applied pi-calculus,
as in similar languages based on equational logics,
knowledge is typically expressed by two relations:
deducibility and static equivalence. Several decision
procedures have been proposed for these relations under
a variety of equational theories. However, each theory
has its particular algorithm, and none has been
implemented so far. We provide a generic procedure for
deducibility and static equivalence that takes as input
any convergent rewrite system. We show that our
algorithm covers most of the existing decision
procedures for convergent theories. We also provide an
efficient implementation and compare it briefly with
the tools ProVerif and KiSs.",
acknowledgement = ack-nhfb,
articleno = "4",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{McKinley:2013:PNH,
author = "Richard McKinley",
title = "Proof Nets for {Herbrand}'s Theorem",
journal = j-TOCL,
volume = "14",
number = "1",
pages = "5:1--5:??",
month = feb,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2422085.2422090",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Feb 20 16:38:47 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "This article explores Herbrand's theorem as the source
of a natural notion of abstract proof object for
classical logic, embodying the ``essence'' of a sequent
calculus proof. We see how to view a calculus of
abstract Herbrand proofs (Herbrand nets) as an analytic
proof system with syntactic cut-elimination. Herbrand
nets can also be seen as a natural generalization of
Miller's expansion tree proofs to a setting including
cut. We demonstrate sequentialization of Herbrand nets
into a sequent calculus {LK{$_H$}}; each net
corresponds to an equivalence class of {LK{$_H$}}
proofs under natural proof transformations. A
surprising property of our cut-reduction algorithm is
that it is non-confluent despite not supporting the
usual examples of non-confluent reduction in classical
logic.",
acknowledgement = ack-nhfb,
articleno = "5",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Larchey-Wendling:2013:NPS,
author = "Dominique Larchey-Wendling and Didier Galmiche",
title = "Nondeterministic Phase Semantics and the
Undecidability of {Boolean} {BI}",
journal = j-TOCL,
volume = "14",
number = "1",
pages = "6:1--6:??",
month = feb,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2422085.2422091",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Feb 20 16:38:47 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We solve the open problem of the decidability of
Boolean BI logic (BBI), which can be considered the
core of separation and spatial logics. For this, we
define a complete phase semantics suitable for BBI and
characterize it as trivial phase semantics. We deduce
an embedding between trivial phase semantics for
intuitionistic linear logic (ILL) and Kripke semantics
for BBI. We single out the elementary fragment of ILL,
which is both undecidable and complete for trivial
phase semantics. Thus, we obtain the undecidability of
BBI.",
acknowledgement = ack-nhfb,
articleno = "6",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bonsangue:2013:SCA,
author = "Marcello M. Bonsangue and Stefan Milius and Alexandra
Silva",
title = "Sound and Complete Axiomatizations of Coalgebraic
Language Equivalence",
journal = j-TOCL,
volume = "14",
number = "1",
pages = "7:1--7:??",
month = feb,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2422085.2422092",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Feb 20 16:38:47 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Coalgebras provide a uniform framework for studying
dynamical systems, including several types of automata.
In this article, we make use of the coalgebraic view on
systems to investigate, in a uniform way, under which
conditions calculi that are sound and complete with
respect to behavioral equivalence can be extended to a
coarser coalgebraic language equivalence, which arises
from a generalized powerset construction that
determinizes coalgebras. We show that soundness and
completeness are established by proving that
expressions modulo axioms of a calculus form the
rational fixpoint of the given type functor. Our main
result is that the rational fixpoint of the functor FT,
where T is a monad describing the branching of the
systems (e.g., non-determinism, weights, probability,
etc.), has as a quotient the rational fixpoint of the
determinized type functor F, a lifting of F to the
category of T -algebras. We apply our framework to the
concrete example of weighted automata, for which we
present a new sound and complete calculus for weighted
language equivalence. As a special case, we obtain
nondeterministic automata in which we recover
Rabinovich's sound and complete calculus for language
equivalence.",
acknowledgement = ack-nhfb,
articleno = "7",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Kartzow:2013:FOL,
author = "Alexander Kartzow",
title = "First-Order Logic on Higher-Order Nested Pushdown
Trees",
journal = j-TOCL,
volume = "14",
number = "2",
pages = "8:1--8:??",
month = jun,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2480759.2480760",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 17 17:37:05 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We introduce a new hierarchy of higher-order nested
pushdown trees generalising Alur et al.'s concept of
nested pushdown trees. Nested pushdown trees are useful
representations of control flows in the verification of
programs with recursive calls of first-order functions.
Higher-order nested pushdown trees are expansions of
unfoldings of graphs generated by higher-order pushdown
systems. Moreover, the class of nested pushdown trees
of level n is uniformly first-order interpretable in
the class of collapsible pushdown graphs of level n +
1. The relationship between the class of higher-order
pushdown graphs and the class of collapsible
higher-order pushdown graphs is not very well
understood. We hope that the further study of the
nested pushdown tree hierarchy leads to a better
understanding of these two hierarchies. In this
article, we are concerned with the first-order model
checking problem on higher-order nested pushdown trees.
We show that the first-order model checking on the
first two levels of this hierarchy is decidable.
Moreover, we obtain an alternating 2-EXPTIME algorithm
for the class of nested pushdown trees of level 1. The
proof technique involves a pseudo-local analysis of
strategies in the Ehrenfeucht-Fra{\"\i}ss{\'e} games on
two identical copies of a nested pushdown tree.
Ordinary locality arguments in the spirit of Gaifman's
lemma do not apply here because nested pushdown trees
tend to have small diameters. We introduce the notion
of relevant ancestors which provide a sufficient
description of the FO$_k$ -type of each element in a
higher-order nested pushdown tree. The local analysis
of these ancestors allows us to prove the existence of
restricted winning strategies in the
Ehrenfeucht-Fra{\"\i}ss{\'e} game. These strategies are
then used to create a first-order model checking
algorithm.",
acknowledgement = ack-nhfb,
articleno = "8",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Gastin:2013:FSA,
author = "Paul Gastin and Nathalie Sznajder",
title = "Fair Synthesis for Asynchronous Distributed Systems",
journal = j-TOCL,
volume = "14",
number = "2",
pages = "9:1--9:??",
month = jun,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2480759.2480761",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 17 17:37:05 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study the synthesis problem in an asynchronous
distributed setting: a finite set of processes interact
locally with an uncontrollable environment and
communicate with each other by sending signals ---
actions controlled by a sender process and that are
immediately received by the target process. The fair
synthesis problem is to come up with a local strategy
for each process such that the resulting fair behaviors
of the system meet a given specification. We consider
external specifications satisfying some natural closure
properties related to the architecture. We present this
new setting for studying the fair synthesis problem for
distributed systems, and give decidability results for
the subclass of networks where communications happen
through a strongly connected graph. We claim that this
framework for distributed synthesis is natural,
convenient and avoids most of the usual sources of
undecidability for the synthesis problem. Hence, it may
open the way to a decidable theory of distributed
synthesis.",
acknowledgement = ack-nhfb,
articleno = "9",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Shakarian:2013:UGA,
author = "Paulo Shakarian and Matthias Broecheler and V. S.
Subrahmanian and Cristian Molinaro",
title = "Using Generalized Annotated Programs to Solve Social
Network Diffusion Optimization Problems",
journal = j-TOCL,
volume = "14",
number = "2",
pages = "10:1--10:??",
month = jun,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2480759.2480762",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 17 17:37:05 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "There has been extensive work in many different fields
on how phenomena of interest (e.g., diseases,
innovation, product adoption) ``diffuse'' through a
social network. As social networks increasingly become
a fabric of society, there is a need to make
``optimal'' decisions with respect to an observed model
of diffusion. For example, in epidemiology, officials
want to find a set of k individuals in a social network
which, if treated, would minimize spread of a disease.
In marketing, campaign managers try to identify a set
of k customers that, if given a free sample, would
generate maximal ``buzz'' about the product. In this
article, we first show that the well-known Generalized
Annotated Program (GAP) paradigm can be used to express
many existing diffusion models. We then define a class
of problems called Social Network Diffusion
Optimization Problems (SNDOPs). SNDOPs have four parts:
(i) a diffusion model expressed as a GAP, (ii) an
objective function we want to optimize with respect to
a given diffusion model, (iii) an integer k {$>$} 0
describing resources (e.g., medication) that can be
placed at nodes, (iv) a logical condition VC that
governs which nodes can have a resource (e.g., only
children above the age of 5 can be treated with a given
medication). We study the computational complexity of
SNDOPs and show both NP-completeness results as well as
results on complexity of approximation. We then develop
an exact and a heuristic algorithm to solve a large
class of SNDOP problems and show that our GREEDY-SNDOPs
algorithm achieves the best possible approximation
ratio that a polynomial algorithm can achieve (unless P
= NP ). We conclude with a prototype experimental
implementation to solve SNDOPs that looks at a
real-world Wikipedia dataset consisting of over 103,000
edges.",
acknowledgement = ack-nhfb,
articleno = "10",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Echenim:2013:ISN,
author = "Mnacho Echenim and Nicolas Peltier",
title = "Instantiation Schemes for Nested Theories",
journal = j-TOCL,
volume = "14",
number = "2",
pages = "11:1--11:??",
month = jun,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2480759.2480763",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 17 17:37:05 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "This article investigates under which conditions
instantiation-based proof procedures can be combined in
a nested way, in order to mechanically construct new
instantiation procedures for richer theories.
Interesting applications in the field of verification
are emphasized, particularly for handling extensions of
the theory of arrays.",
acknowledgement = ack-nhfb,
articleno = "11",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Simari:2013:PAQ,
author = "Gerardo I. Simari and John P. Dickerson and Amy Sliva
and V. S. Subrahmanian",
title = "Parallel Abductive Query Answering in Probabilistic
Logic Programs",
journal = j-TOCL,
volume = "14",
number = "2",
pages = "12:1--12:??",
month = jun,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2480759.2480764",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 17 17:37:05 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Action-probabilistic logic programs ( ap -programs)
are a class of probabilistic logic programs that have
been extensively used during the last few years for
modeling behaviors of entities. Rules in ap -programs
have the form ``If the environment in which entity E
operates satisfies certain conditions, then the
probability that E will take some action A is between L
and U ''. Given an ap -program, we are interested in
trying to change the environment, subject to some
constraints, so that the probability that entity E
takes some action (or combination of actions) is
maximized. This is called the Basic Abductive Query
Answering Problem (BAQA). We first formally define and
study the complexity of BAQA, and then go on to provide
an exact (exponential time) algorithm to solve it,
followed by more efficient algorithms for specific
subclasses of the problem. We also develop appropriate
heuristics to solve BAQA efficiently. The second
problem, called the Cost-based Query Answering (CBQA)
problem checks to see if there is some way of achieving
a desired action (or set of actions) with a probability
exceeding a threshold, given certain costs. We first
formally define and study an exact (intractable)
approach to CBQA, and then go on to propose a more
efficient algorithm for a specific subclass of ap
-programs that builds on the results for the basic
version of this problem. We also develop the first
algorithms for parallel evaluation of CBQA. We conclude
with an extensive report on experimental evaluations
performed over prototype implementations of the
algorithms developed for both BAQA and CBQA, showing
that our parallel algorithms work well in practice.",
acknowledgement = ack-nhfb,
articleno = "12",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Kontchakov:2013:TLC,
author = "Roman Kontchakov and Yavor Nenov and Ian
Pratt-Hartmann and Michael Zakharyaschev",
title = "Topological Logics with Connectedness over {Euclidean}
Spaces",
journal = j-TOCL,
volume = "14",
number = "2",
pages = "13:1--13:??",
month = jun,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2480759.2480765",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 17 17:37:05 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We consider the quantifier-free languages, Bc and Bc
${}^\circ $, obtained by augmenting the signature of
Boolean algebras with a unary predicate representing,
respectively, the property of being connected, and the
property of having a connected interior. These
languages are interpreted over the regular closed sets
of R$^n$ ( n {$>$}= 2) and, additionally, over the
regular closed semilinear sets of R$^n$. The resulting
logics are examples of formalisms that have recently
been proposed in the Artificial Intelligence literature
under the rubric Qualitative Spatial Reasoning. We
prove that the satisfiability problem for Bc is
undecidable over the regular closed semilinear sets in
all dimensions greater than 1, and that the
satisfiability problem for Bc and Bc ${}^\circ $ is
undecidable over both the regular closed sets and the
regular closed semilinear sets in the Euclidean plane.
However, we also prove that the satisfiability problem
for Bc ${}^\circ $ is NP-complete over the regular
closed sets in all dimensions greater than 2, while the
corresponding problem for the regular closed semilinear
sets is ExpTime-complete. Our results show, in
particular, that spatial reasoning is much harder over
Euclidean spaces than over arbitrary topological
spaces.",
acknowledgement = ack-nhfb,
articleno = "13",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Delgrande:2013:MTA,
author = "James Delgrande and Torsten Schaub and Hans Tompits
and Stefan Woltran",
title = "A Model-Theoretic Approach to Belief Change in Answer
Set Programming",
journal = j-TOCL,
volume = "14",
number = "2",
pages = "14:1--14:??",
month = jun,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2480759.2480766",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 17 17:37:05 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We address the problem of belief change in
(nonmonotonic) logic programming under answer set
semantics. Our formal techniques are analogous to those
of distance-based belief revision in propositional
logic. In particular, we build upon the model theory of
logic programs furnished by SE interpretations, where
an SE interpretation is a model of a logic program in
the same way that a classical interpretation is a model
of a propositional formula. Hence we extend techniques
from the area of belief revision based on distance
between models to belief change in logic programs. We
first consider belief revision: for logic programs P
and Q, the goal is to determine a program R that
corresponds to the revision of P by Q, denoted P * Q.
We investigate several operators, including (logic
program) expansion and two revision operators based on
the distance between the SE models of logic programs.
It proves to be the case that expansion is an
interesting operator in its own right, unlike in
classical belief revision where it is relatively
uninteresting. Expansion and revision are shown to
satisfy a suite of interesting properties; in
particular, our revision operators satisfy all or
nearly all of the AGM postulates for revision. We next
consider approaches for merging a set of logic
programs, P$_1$, ..., P$_n$. Again, our formal
techniques are based on notions of relative distance
between the SE models of the logic programs. Two
approaches are examined. The first informally selects
for each program P$_i$ those models of P$_i$ that vary
the least from models of the other programs. The second
approach informally selects those models of a program
P$_0$ that are closest to the models of programs P$_1$,
..., P$_n$. In this case, P$_0$ can be thought of as a
set of database integrity constraints. We examine these
operators with regards to how they satisfy relevant
postulate sets. Last, we present encodings for
computing the revision as well as the merging of logic
programs within the same logic programming framework.
This gives rise to a direct implementation of our
approach in terms of off-the-shelf answer set solvers.
These encodings also reflect the fact that our change
operators do not increase the complexity of the base
formalism.",
acknowledgement = ack-nhfb,
articleno = "14",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Gebser:2013:TCL,
author = "Martin Gebser and Torsten Schaub",
title = "Tableau Calculi for Logic Programs under Answer Set
Semantics",
journal = j-TOCL,
volume = "14",
number = "2",
pages = "15:1--15:??",
month = jun,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2480759.2480767",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 17 17:37:05 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We introduce formal proof systems based on tableau
methods for analyzing computations in Answer Set
Programming (ASP). Our approach furnishes fine-grained
instruments for characterizing operations as well as
strategies of ASP solvers. The granularity is detailed
enough to capture a variety of propagation and choice
methods of algorithms used for ASP solving, also
incorporating SAT-based and conflict-driven learning
approaches to some extent. This provides us with a
uniform setting for identifying and comparing
fundamental properties of ASP solving approaches. In
particular, we investigate their proof complexities and
show that the run-times of best-case computations can
vary exponentially between different existing ASP
solvers. Apart from providing a framework for comparing
ASP solving approaches, our characterizations also
contribute to their understanding by pinning down the
constitutive atomic operations. Furthermore, our
framework is flexible enough to integrate new inference
patterns, and so to study their relation to existing
ones. To this end, we generalize our approach and
provide an extensible basis aiming at a modular
incorporation of additional language constructs. This
is exemplified by augmenting our basic tableau methods
with cardinality constraints and disjunctions.",
acknowledgement = ack-nhfb,
articleno = "15",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Alferes:2013:QDP,
author = "Jos{\'e} J{\'u}lio Alferes and Matthias Knorr and
Terrance Swift",
title = "Query-Driven Procedures for Hybrid {MKNF} Knowledge
Bases",
journal = j-TOCL,
volume = "14",
number = "2",
pages = "16:1--16:??",
month = jun,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2480759.2480768",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 17 17:37:05 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Hybrid MKNF knowledge bases are one of the most
prominent tightly integrated combinations of open-world
ontology languages with closed-world (nonmonotonic)
rule paradigms. Based on the logic of minimal knowledge
and negation as failure (MKNF), the definition of
Hybrid MKNF is parametric on the description logic (DL)
underlying the ontology language, in the sense that
nonmonotonic rules can extend any decidable DL
language. Two related semantics have been defined for
Hybrid MKNF: one that is based on the Stable Model
Semantics for logic programs and one on the
Well-Founded Semantics (WFS). Under WFS, the definition
of Hybrid MKNF relies on a bottom-up computation that
has polynomial data complexity whenever the DL language
is tractable. Here we define a general query-driven
procedure for Hybrid MKNF that is sound with respect to
the stable model-based semantics, and sound and
complete with respect to its WFS variant. This
procedure is able to answer a slightly restricted form
of conjunctive queries, and is based on tabled rule
evaluation extended with an external oracle that
captures reasoning within the ontology. Such an
(abstract) oracle receives as input a query along with
knowledge already derived, and replies with a (possibly
empty) set of atoms, defined in the rules, whose truth
would suffice to prove the initial query. With
appropriate assumptions on the complexity of the
abstract oracle, the general procedure maintains the
data complexity of the WFS for Hybrid MKNF knowledge
bases. To illustrate this approach, we provide a
concrete oracle for EL$^+$, a fragment of the
lightweight DL EL$^{++}$. Such an oracle has practical
use, as EL$^{++}$ is the language underlying OWL 2 EL,
which is part of the W3C recommendations for the
Semantic Web, and is tractable for reasoning tasks such
as subsumption. We show that query-driven Hybrid MKNF
preserves polynomial data complexity when using the
EL$^+$ oracle and WFS.",
acknowledgement = ack-nhfb,
articleno = "16",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Wittocx:2013:CPF,
author = "Johan Wittocx and Marc Denecker and Maurice
Bruynooghe",
title = "Constraint Propagation for First-Order Logic and
Inductive Definitions",
journal = j-TOCL,
volume = "14",
number = "3",
pages = "17:1--17:??",
month = aug,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2499937.2499938",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Aug 28 17:07:40 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In Constraint Programming, constraint propagation is a
basic component of constraint satisfaction
solvers. Here we study constraint propagation as a
basic form of inference in the context of first-order
logic (FO) and extensions with inductive definitions
(FO(ID)) and aggregates (FO(AGG)). In a first, semantic
approach, a theory of propagators and constraint
propagation is developed for theories in the context of
three-valued interpretations. We present an algorithm
with polynomial-time data complexity. We show that
constraint propagation in this manner can be
represented by a datalog program. In a second, symbolic
approach, the semantic algorithm is lifted to a
constraint propagation algorithm in symbolic
structures, symbolic representations of classes of
structures. The third part of the article is an
overview of existing and potential applications of
constraint propagation for model generation, grounding,
interactive search problems, approximate methods for $
\exists \forall $ SO problems, and approximate query
answering in incomplete databases.",
acknowledgement = ack-nhfb,
articleno = "17",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Praveen:2013:DTH,
author = "M. Praveen",
title = "Does Treewidth Help in Modal Satisfiability?",
journal = j-TOCL,
volume = "14",
number = "3",
pages = "18:1--18:??",
month = aug,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2499937.2499939",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Aug 28 17:07:40 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Many tractable algorithms for solving the Constraint
Satisfaction Problem ( Csp) have been developed using
the notion of the treewidth of some graph derived from
the input Csp instance. In particular, the incidence
graph of the Csp instance is one such graph. We
introduce the notion of an incidence graph for modal
logic formulas in a certain normal form. We investigate
the parameterized complexity of modal satisfiability
with the modal depth of the formula and the treewidth
of the incidence graph as parameters. For various
combinations of Euclidean, reflexive, symmetric, and
transitive models, we show either that modal
satisfiability is Fixed Parameter Tractable (Fpt), or
that it is W[1]-hard. In particular, modal
satisfiability in general models is Fpt, while it is
W[1]-hard in transitive models. As might be expected,
modal satisfiability in transitive and Euclidean models
is Fpt.",
acknowledgement = ack-nhfb,
articleno = "18",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Tan:2013:GRP,
author = "Tony Tan",
title = "Graph Reachability and Pebble Automata over Infinite
Alphabets",
journal = j-TOCL,
volume = "14",
number = "3",
pages = "19:1--19:??",
month = aug,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2499937.2499940",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Aug 28 17:07:40 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Let D denote an infinite alphabet --- a set that
consists of infinitely many symbols. A word $ w = a_0
b_0 a_1 b_1 \cdot \cdot \cdot a_n b_n $ of even length
over {$D$} can be viewed as a directed graph {$ G_w $}
whose vertices are the symbols that appear in $w$, and
the edges are $ (a_0, b_0), (a_1, b_1), \ldots {},
(a_n, b_n) $. For a positive integer $m$, define a
language {$ R_m $} such that a word {$ w = a_0 b_0
\cdot \cdot \cdot a_n b_n \in R_m $} if and only if
there is a path in the graph {$ G_w $} of length $ \leq
m $ from the vertex $ a_0 $ to the vertex $ b_n $. We
establish the following hierarchy theorem for pebble
automata over infinite alphabet. For every positive
integer $k$, (i) there exists a $k$-pebble automaton
that accepts the language {$ R_{2k - 1} $}; (ii) there
is no $k$-pebble automaton that accepts the language {$
R_{2k + 1 - 2} $}. Using this fact, we establish the
following main results in this article: (a) a strict
hierarchy of the pebble automata languages based on the
number of pebbles; (b) the separation of monadic second
order logic from the pebble automata languages; (c) the
separation of one-way deterministic register automata
languages from pebble automata languages.",
acknowledgement = ack-nhfb,
articleno = "19",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Beyersdorff:2013:PCD,
author = "Olaf Beyersdorff and Nicola Galesi and Massimo
Lauria",
title = "Parameterized Complexity of {DPLL} Search Procedures",
journal = j-TOCL,
volume = "14",
number = "3",
pages = "20:1--20:??",
month = aug,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2499937.2499941",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Aug 28 17:07:40 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study the performance of DPLL algorithms on
parameterized problems. In particular, we investigate
how difficult it is to decide whether small solutions
exist for satisfiability and other combinatorial
problems. For this purpose we develop a Prover-Delayer
game that models the running time of DPLL procedures
and we establish an information-theoretic method to
obtain lower bounds to the running time of
parameterized DPLL procedures. We illustrate this
technique by showing lower bounds to the parameterized
pigeonhole principle and to the ordering principle. As
our main application we study the DPLL procedure for
the problem of deciding whether a graph has a small
clique. We show that proving the absence of a k -clique
requires {$ n^{\Omega (k)} $} steps for a nontrivial
distribution of graphs close to the critical threshold.
For the restricted case of tree-like Parameterized
Resolution, this result answers a question asked by
Beyersdorff et al. [2012] of understanding the
Resolution complexity of this family of formulas.",
acknowledgement = ack-nhfb,
articleno = "20",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Charalambidis:2013:EHO,
author = "Angelos Charalambidis and Konstantinos Handjopoulos
and Panagiotis Rondogiannis and William W. Wadge",
title = "Extensional Higher-Order Logic Programming",
journal = j-TOCL,
volume = "14",
number = "3",
pages = "21:1--21:??",
month = aug,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2499937.2499942",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Aug 28 17:07:40 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We propose a purely extensional semantics for
higher-order logic programming. In this semantics
program predicates denote sets of ordered tuples, and
two predicates are equal iff they are equal as sets.
Moreover, every program has a unique minimum Herbrand
model which is the greatest lower bound of all Herbrand
models of the program and the least fixed-point of an
immediate consequence operator. We also propose an
SLD-resolution proof system which is proven sound and
complete with respect to the minimum Herbrand model
semantics. In other words, we provide a purely
extensional theoretical framework for higher-order
logic programming which generalizes the familiar theory
of classical (first-order) logic programming.",
acknowledgement = ack-nhfb,
articleno = "21",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Albert:2013:IRU,
author = "Elvira Albert and Samir Genaim and Abu Naser Masud",
title = "On the Inference of Resource Usage Upper and Lower
Bounds",
journal = j-TOCL,
volume = "14",
number = "3",
pages = "22:1--22:??",
month = aug,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2499937.2499943",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Aug 28 17:07:40 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Cost analysis aims at determining the amount of
resources required to run a program in terms of its
input data sizes. The most challenging step is to infer
the cost of executing the loops in the program. This
requires bounding the number of iterations of each loop
and finding tight bounds for the cost of each of its
iterations. This article presents a novel approach to
infer upper and lower bounds from cost relations. These
relations are an extended form of standard recurrence
equations that can be nondeterministic, contain inexact
size constraints and have multiple arguments that
increase and/or decrease. We propose novel techniques
to automatically transform cost relations into
worst-case and best-case deterministic one-argument
recurrence relations. The solution of each recursive
relation provides a precise upper-bound and lower-bound
for executing a corresponding loop in the program.
Importantly, since the approach is developed at the
level of the cost equations, our techniques are
programming language independent.",
acknowledgement = ack-nhfb,
articleno = "22",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Sietsma:2013:CKE,
author = "Floor Sietsma and Krzysztof R. Apt",
title = "Common Knowledge in Email Exchanges",
journal = j-TOCL,
volume = "14",
number = "3",
pages = "23:1--23:??",
month = aug,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2499937.2499944",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Aug 28 17:07:40 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We consider a framework in which a group of agents
communicates by means of emails, with the possibility
of replies, forwards and blind carbon copies (BCC). We
study the epistemic consequences of such email
exchanges by introducing an appropriate epistemic
language and semantics. This allows us to find out what
agents learn from the emails they receive and to
determine when a group of agents acquires common
knowledge of the fact that an email was sent. We also
show that in our framework from the epistemic point of
view the BCC feature of emails cannot be simulated
using messages without BCC recipients.",
acknowledgement = ack-nhfb,
articleno = "23",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Herzig:2013:PUO,
author = "Andreas Herzig and Jerome Lang and Pierre Marquis",
title = "Propositional Update Operators Based on
Formula\slash Literal Dependence",
journal = j-TOCL,
volume = "14",
number = "3",
pages = "24:1--24:??",
month = aug,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2499937.2499945",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Aug 28 17:07:40 MDT 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present and study a general family of belief update
operators in a propositional setting. Its operators are
based on formula/ literal dependence, which is more
fine-grained than the notion of formula/ variable
dependence that was proposed in the literature:
formula/variable dependence is a particular case of
formula/literal dependence. Our update operators are
defined according to the ``forget-then-conjoin''
scheme: updating a belief base by an input formula
consists in first forgetting in the base every literal
on which the input formula has a negative influence,
and then conjoining the resulting base with the input
formula. The operators of our family differ by the
underlying notion of formula/literal dependence, which
may be defined syntactically or semantically, and which
may or may not exploit further information like known
persistent literals and pre-set dependencies. We argue
that this allows to handle the frame problem and the
ramification problem in a more appropriate way. We
evaluate the update operators of our family w.r.t. two
important dimensions: the logical dimension, by
checking the status of the Katsuno-Mendelzon postulates
for update, and the computational dimension, by
identifying the complexity of a number of decision
problems (including model checking, consistency and
inference), both in the general case and in some
restricted cases, as well as by studying compactability
issues. It follows that several operators of our family
are interesting alternatives to previous belief update
operators.",
acknowledgement = ack-nhfb,
articleno = "24",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Kazana:2013:EMS,
author = "Wojciech Kazana and Luc Segoufin",
title = "Enumeration of monadic second-order queries on trees",
journal = j-TOCL,
volume = "14",
number = "4",
pages = "25:1--25:??",
month = nov,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2528928",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Dec 3 18:27:46 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We consider the enumeration problem of Monadic
Second-Order (MSO) queries with first-order free
variables over trees. In Bagan [2006] it was shown that
this problem is in CONSTANT-DELAY$_{lin}$. An
enumeration problem belongs to CONSTANT-DELAY$_{lin}$
if for an input structure of size n it can be solved
by:\par
--- an $ O(n)$ precomputation phase building an index
structure,\par
--- followed by a phase enumerating the answers with no
repetition and a constant delay between two consecutive
outputs.\par
In this article we give a different proof of this
result based on the deterministic factorization forest
decomposition theorem of Colcombet [2007].",
acknowledgement = ack-nhfb,
articleno = "25",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Heras:2013:CPH,
author = "J{\'o}nathan Heras and Thierry Coquand and Anders
M{\"o}rtberg and Vincent Siles",
title = "Computing persistent homology within {Coq\slash
SSReflect}",
journal = j-TOCL,
volume = "14",
number = "4",
pages = "26:1--26:??",
month = nov,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2528929",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Dec 3 18:27:46 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Persistent homology is one of the most active branches
of computational algebraic topology with applications
in several contexts such as optical character
recognition or analysis of point cloud data. In this
article, we report on the formal development of
certified programs to compute persistent Betti numbers,
an instrumental tool of persistent homology, using the
C oq proof assistant together with the SSReflect
extension. To this aim it has been necessary to
formalize the underlying mathematical theory of these
algorithms. This is another example showing that
interactive theorem provers have reached a point where
they are mature enough to tackle the formalization of
nontrivial mathematical theories.",
acknowledgement = ack-nhfb,
articleno = "26",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Lahav:2013:USF,
author = "Ori Lahav and Arnon Avron",
title = "A unified semantic framework for fully structural
propositional sequent systems",
journal = j-TOCL,
volume = "14",
number = "4",
pages = "27:1--27:??",
month = nov,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2528930",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Dec 3 18:27:46 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We identify a large family of fully structural
propositional sequent systems, which we call basic
systems. We present a general uniform method for
providing (potentially, nondeterministic) strongly
sound and complete Kripke-style semantics, which is
applicable for every system of this family. In
addition, this method can also be applied when: (i)
some formulas are not allowed to appear in derivations,
(ii) some formulas are not allowed to serve as cut
formulas, and (iii) some instances of the identity
axiom are not allowed to be used. This naturally leads
to new semantic characterizations of analyticity
(global subformula property), cut admissibility and
axiom expansion in basic systems. We provide a large
variety of examples showing that many soundness and
completeness theorems for different sequent systems, as
well as analyticity, cut admissibility, and axiom
expansion results, easily follow using the general
method of this article.",
acknowledgement = ack-nhfb,
articleno = "27",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Gaintzarain:2013:LFM,
author = "Jose Gaintzarain and Paqui Lucio",
title = "Logical foundations for more expressive declarative
temporal logic programming languages",
journal = j-TOCL,
volume = "14",
number = "4",
pages = "28:1--28:??",
month = nov,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2528931",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Dec 3 18:27:46 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In this article, we present a declarative
propositional temporal logic programming language
called TeDiLog that is a combination of the temporal
and disjunctive paradigms in logic programming. TeDiLog
is, syntactically, a sublanguage of the well-known
Propositional Linear-time Temporal Logic (PLTL).
TeDiLog allows both eventualities and always-formulas
to occur in clause heads and also in clause bodies. To
the best of our knowledge, TeDiLog is the first
declarative temporal logic programming language that
achieves this high degree of expressiveness. We
establish the logical foundations of our proposal by
formally defining operational and logical semantics for
TeDiLog and by proving their equivalence. The
operational semantics of TeDiLog relies on a
restriction of the invariant-free temporal resolution
procedure for PLTL that was introduced by Gaintzarain
et al. in [2013]. We define a fixpoint semantics that
captures the reverse (bottom-up) operational mechanism
and prove its equivalence with the logical semantics.
We also provide illustrative examples and comparison
with other proposals.",
acknowledgement = ack-nhfb,
articleno = "28",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Danvy:2013:TST,
author = "Olivier Danvy and Ian Zerny",
title = "Three syntactic theories for combinatory graph
reduction",
journal = j-TOCL,
volume = "14",
number = "4",
pages = "29:1--29:??",
month = nov,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2528932",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Dec 3 18:27:46 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present a purely syntactic theory of graph
reduction for the canonical combinators S, K, and I,
where graph vertices are represented with evaluation
contexts and let expressions. We express this first
syntactic theory as a storeless reduction semantics of
combinatory terms. We then factor out the introduction
of let expressions to denote as many graph vertices as
possible upfront instead of on demand. The factored
terms can be interpreted as term graphs in the sense of
Barendregt et al. We express this second syntactic
theory, which we prove equivalent to the first, as a
storeless reduction semantics of combinatory term
graphs. We then recast let bindings as bindings in a
global store, thus shifting, in Strachey's words, from
denotable entities to storable entities. The
store-based terms can still be interpreted as term
graphs. We express this third syntactic theory, which
we prove equivalent to the second, as a store-based
reduction semantics of combinatory term graphs. We then
refocus this store-based reduction semantics into a
store-based abstract machine. The architecture of this
store-based abstract machine coincides with that of
Turner's original reduction machine. The three
syntactic theories presented here therefore properly
account for combinatory graph reduction As We Know It.
These three syntactic theories scale to handling the Y
combinator. This article therefore illustrates the
scientific consensus of theoreticians and implementors
about graph reduction: it is the same combinatory
elephant.",
acknowledgement = ack-nhfb,
articleno = "29",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bodirsky:2013:CST,
author = "Manuel Bodirsky and H. Dugald Macpherson and Johan
Thapper",
title = "Constraint satisfaction tractability from semi-lattice
operations on infinite sets",
journal = j-TOCL,
volume = "14",
number = "4",
pages = "30:1--30:??",
month = nov,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2528933",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Dec 3 18:27:46 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A famous result by Jeavons, Cohen, and Gyssens shows
that every Constraint Satisfaction Problem (CSP) where
the constraints are preserved by a semi-lattice
operation can be solved in polynomial time. This is one
of the basic facts for the so-called universal
algebraic approach to a systematic theory of
tractability and hardness in finite domain constraint
satisfaction. Not surprisingly, the theorem of Jeavons
et al. fails for arbitrary infinite domain CSPs. Many
CSPs of practical interest, though, and in particular
those CSPs that are motivated by qualitative reasoning
calculi from artificial intelligence, can be formulated
with constraint languages that are rather well-behaved
from a model-theoretic point of view. In particular,
the automorphism group of these constraint languages
tends to be large in the sense that the number of
orbits of $n$-subsets of the automorphism group is
bounded by some function in $n$. In this article we
present a generalization of the theorem by Jeavons et
al. to infinite domain CSPs where the number of orbits
of $n$-subsets grows subexponentially in $n$, and prove
that preservation under a semi-lattice operation for
such CSPs implies polynomial-time tractability. Unlike
the result of Jeavons et al., this includes CSPs that
cannot be solved by Datalog.",
acknowledgement = ack-nhfb,
articleno = "30",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Ketema:2013:LUB,
author = "Jeroen Ketema and Jakob Grue Simonsen",
title = "Least upper bounds on the size of confluence and
{Church--Rosser} diagrams in term rewriting and $
\lambda $-calculus",
journal = j-TOCL,
volume = "14",
number = "4",
pages = "31:1--31:??",
month = nov,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2528934",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Dec 3 18:27:46 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study confluence and the Church--Rosser property in
term rewriting and $ \lambda $-calculus with explicit
bounds on term sizes and reduction lengths. Given a
system $R$, we are interested in the lengths of the
reductions in the smallest valleys $ t \rightarrow * s
' * \leftarrow t '$ expressed as a function:\par
--- for confluence a function $ {\rm vs}_R(m, n)$ where
the valleys are for peaks $ t \leftarrow s \rightarrow
* t '$ with $s$ of size at most $m$ and the reductions
of maximum length $n$, and\par
--- for the Church--Rosser property a function $ {\rm
cvs}_R (m, n)$ where the valleys are for conversions $
t \leftrightarrow * t$ with $t$ and $ t'$ of size at
most $m$ and the conversion of maximum length
$n$.\par
For confluent Term Rewriting Systems (TRSs), we prove
that $ {\rm vs}_R$ is a total computable function, and
for linear such systems that $ {\rm cvs}_R$ is a total
computable function. Conversely, we show that every
total computable function is the lower bound on the
functions $ {\rm vs}_R (m, n)$ and $ {\rm cvs}_R (m,
n)$ for some TRS {$R$}: In particular, we show that for
every total computable function $ \varphi : N
\rightarrow N$ there is a TRS $R$ with a single term
$s$ such that $ {\rm vs}_R (| s |, n) \geq \varphi (n)$
and $ {\rm cvs}_R (n, n) \geq \varphi (n)$ for all n.
For orthogonal TRSs $R$ we prove that there is a
constant $k$ such that: (a) $ {\rm vs}_R (m, n)$ is
bounded from above by a function exponential in $k$ and
(b) $ {\rm cvs}_R (m, n)$ is bounded from above by a
function in the fourth level of the Grzegorczyk
hierarchy. Similarly, for $ \lambda $-calculus, we show
that $ {\rm vs}_R(m, n)$ is bounded from above by a
function in the fourth level of the Grzegorczyk
hierarchy.",
acknowledgement = ack-nhfb,
articleno = "31",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Rabe:2013:LRL,
author = "Florian Rabe and Kristina Sojakova",
title = "Logical relations for a logical framework",
journal = j-TOCL,
volume = "14",
number = "4",
pages = "32:1--32:??",
month = nov,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2536740.2536741",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Dec 3 18:27:46 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Logical relations are a central concept used to study
various higher-order type theories and occur frequently
in the proofs of a wide variety of meta-theorems.
Besides extending the logical relation principle to
more general languages, an important research question
has been how to represent and thus verify logical
relation arguments in logical frameworks. We formulate
a theory of logical relations for Dependent Type Theory
(DTT) with \beta \eta -equality which guarantees that
any valid logical relation satisfies the Basic Lemma.
Our definition is syntactic and reflective in the sense
that a relation at a type is represented as a DTT type
family but also permits expressing certain semantic
definitions. We use the Edinburgh Logical Framework
(LF) incarnation of DTT and implement our notion of
logical relations in the type-checker Twelf. This
enables us to formalize and mechanically decide the
validity of logical relation arguments. Furthermore,
our implementation includes a module system so that
logical relations can be built modularly. We validate
our approach by formalizing and verifying several
syntactic and semantic meta-theorems in Twelf.
Moreover, we show how object languages encoded in DTT
can inherit a notion of logical relation from the
logical framework.",
acknowledgement = ack-nhfb,
articleno = "32",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Chen:2013:VLD,
author = "Taolue Chen and Marco Diciolla and Marta Kwiatkowska
and Alexandru Mereacre",
title = "Verification of linear duration properties over
continuous-time {Markov} chains",
journal = j-TOCL,
volume = "14",
number = "4",
pages = "33:1--33:??",
month = nov,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2528935",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Dec 3 18:27:46 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Stochastic modelling and algorithmic verification
techniques have been proved useful in analysing and
detecting unusual trends in performance and energy
usage of systems such as power management controllers
and wireless sensor devices. Many important properties
are dependent on the cumulated time that the device
spends in certain states, possibly intermittently. We
study the problem of verifying continuous-time Markov
Chains (CTMCs) against Linear Duration Properties
(LDP), that is, properties stated as conjunctions of
linear constraints over the total duration of time
spent in states that satisfy a given property. We
identify two classes of LDP properties, Eventuality
Duration Properties (EDP) and Invariance Duration
Properties (IDP), respectively referring to the
reachability of a set of goal states, within a time
bound; and the continuous satisfaction of a duration
property over an execution path. The central question
that we address is how to compute the probability of
the set of infinite timed paths of the CTMC that
satisfy a given LDP. We present algorithms to
approximate these probabilities up to a given
precision, stating their complexity and error bounds.
The algorithms mainly employ an adaptation of
uniformisation and the computation of volumes of
multidimensional integrals under systems of linear
constraints, together with different mechanisms to
bound the errors.",
acknowledgement = ack-nhfb,
articleno = "33",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Dyckhoff:2013:APT,
author = "Roy Dyckhoff and Mehrnoosh Sadrzadeh and Julien
Truffaut",
title = "Algebra, proof theory and applications for an
intuitionistic logic of propositions, actions and
adjoint modal operators",
journal = j-TOCL,
volume = "14",
number = "4",
pages = "34:1--34:??",
month = nov,
year = "2013",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2536740.2536742",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Dec 3 18:27:46 MST 2013",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We develop a cut-free nested sequent calculus as basis
for a proof search procedure for an intuitionistic
modal logic of actions and propositions. The actions
act on propositions via a dynamic modality (the weakest
precondition of program logics), whose left adjoint we
refer to as ``update'' (the strongest postcondition ).
The logic has agent-indexed adjoint pairs of epistemic
modalities: the left adjoints encode agents'
uncertainties and the right adjoints encode their
beliefs. The rules for the ``update'' modality encode
learning as a result of discarding uncertainty. We
prove admissibility of Cut, and hence the soundness and
completeness of the logic with respect to an algebraic
semantics. We interpret the logic on epistemic
scenarios that consist of honest and dishonest
communication actions, add assumption rules to encode
them, and prove that the calculus with the assumption
rules still has the admissibility results. We apply the
calculus to encode (and allow reasoning about) the
classic epistemic puzzles of dirty children (a.k.a.
``muddy children'') and drinking logicians and some
versions with dishonesty or noise; we also give an
application where the actions are movements of a robot
rather than announcements.",
acknowledgement = ack-nhfb,
articleno = "34",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bauer:2014:PCF,
author = "Matthew S. Bauer",
title = "A {PSPACE-complete} first-order fragment of
computability logic",
journal = j-TOCL,
volume = "15",
number = "1",
pages = "1:1--1:??",
month = feb,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2559949",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Feb 28 17:01:18 MST 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In a recently launched research program for developing
logic as a formal theory of (interactive)
computability, several very interesting logics have
been introduced and axiomatized. These fragments of the
larger Computability Logic aim not only to describe
what can be computed, but also provide a mechanism for
extracting computational algorithms from proofs. Among
the most expressive and fundamental of these is CL4,
known to be (constructively) sound and complete with
respect to the underlying computational semantics.
Furthermore, the $\forall$, $\exists$-free fragment of
CL4 was shown to be decidable in polynomial space. The
present work extends this result and proves that this
fragment is, in fact, PSPACE-complete.",
acknowledgement = ack-nhfb,
articleno = "1",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Beckmann:2014:IWL,
author = "Arnold Beckmann and Samuel R. Buss",
title = "Improved witnessing and local improvement principles
for second-order bounded arithmetic",
journal = j-TOCL,
volume = "15",
number = "1",
pages = "2:1--2:??",
month = feb,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2559950",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Feb 28 17:01:18 MST 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "This article concerns the second-order systems $U^1_2$
and $V^1_2$ of bounded arithmetic, which have
proof-theoretic strengths corresponding to
polynomial-space and exponential-time computation. We
formulate improved witnessing theorems for these two
theories by using $S^1_2$ as a base theory for proving
the correctness of the polynomial-space or
exponential-time witnessing functions. We develop the
theory of nondeterministic polynomial-space
computation, including Savitch's theorem, in $U^1_2$.
Kolodziejczyk et al. [2011] have introduced local
improvement properties to characterize the provably
total NP functions of these second-order theories. We
show that the strengths of their local improvement
principles over $U^1_2$ and $V^1_2$ depend primarily on
the topology of the underlying graph, not the number of
rounds in the local improvement games. The theory
$U^1_2$ proves the local improvement principle for
linear graphs even without restricting to
logarithmically many rounds. The local improvement
principle for grid graphs with only
logarithmically-many rounds is complete for the
provably total NP search problems of $V^1_2$. Related
results are obtained for local improvement principles
with one improvement round and for local improvement
over rectangular grids.",
acknowledgement = ack-nhfb,
articleno = "2",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bonchi:2014:ACD,
author = "Filippo Bonchi and Marcello M. Bonsangue and Helle H.
Hansen and Prakash Panangaden and Jan J. M. M. Rutten
and Alexandra Silva",
title = "Algebra-coalgebra duality in {Brzozowski}'s
minimization algorithm",
journal = j-TOCL,
volume = "15",
number = "1",
pages = "3:1--3:??",
month = feb,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2490818",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Feb 28 17:01:18 MST 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We give a new presentation of Brzozowski's algorithm
to minimize finite automata using elementary facts from
universal algebra and coalgebra and building on earlier
work by Arbib and Manes on a categorical presentation
of Kalman duality between reachability and
observability. This leads to a simple proof of its
correctness and opens the door to further
generalizations. Notably, we derive algorithms to
obtain minimal language equivalent automata from Moore
nondeterministic and weighted automata.",
acknowledgement = ack-nhfb,
articleno = "3",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Fernandez-Duque:2014:NFA,
author = "David Fern{\'a}ndez-Duque",
title = "Non-finite axiomatizability of dynamic topological
logic",
journal = j-TOCL,
volume = "15",
number = "1",
pages = "4:1--4:??",
month = feb,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2489334",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Feb 28 17:01:18 MST 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Dynamic topological logic (DTL) is a polymodal logic
designed for reasoning about dynamic topological
systems. These are pairs $ \langle X, f \rangle $,
where $X$ is a topological space and $ f : X \to X $ is
continuous. DTL uses a language L which combines the
topological S4 modality $ \Square $ with temporal
operators from linear temporal logic.\par
Recently, we gave a sound and complete axiomatization
DTL$^*$ for an extension of the logic to the language
L$^*$, where $ \Diamond $ is allowed to act on finite
sets of formulas and is interpreted as a tangled
closure operator. No complete axiomatization is known
in the language L, although one proof system, which we
shall call KM, was conjectured to be complete by Kremer
and Mints.\par
In this article, we show that given any language L'
such that L \subseteq L' \subseteq L$^*$, the set of
valid formulas of L' is not finitely axiomatizable. It
follows, in particular, that KM is incomplete.",
acknowledgement = ack-nhfb,
articleno = "4",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bruttomesso:2014:QFI,
author = "Roberto Bruttomesso and Silvio Ghilardi and Silvio
Ranise",
title = "Quantifier-free interpolation in combinations of
equality interpolating theories",
journal = j-TOCL,
volume = "15",
number = "1",
pages = "5:1--5:??",
month = feb,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2490253",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Feb 28 17:01:18 MST 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The use of interpolants in verification is gaining
more and more importance. Since theories used in
applications are usually obtained as (disjoint)
combinations of simpler theories, it is important to
modularly reuse interpolation algorithms for the
component theories. We show that a sufficient and
necessary condition to do this for quantifier-free
interpolation is that the component theories have the
strong ( sub -) amalgamation property. Then, we provide
an equivalent syntactic characterization and show that
such characterization covers most theories commonly
employed in verification. Finally, we design a combined
quantifier-free interpolation algorithm capable of
handling both convex and nonconvex theories; this
algorithm subsumes and extends most existing work on
combined interpolation.",
acknowledgement = ack-nhfb,
articleno = "5",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Atserias:2014:DLB,
author = "Albert Atserias and Anuj Dawar",
title = "Degree lower bounds of tower-type for approximating
formulas with parity quantifiers",
journal = j-TOCL,
volume = "15",
number = "1",
pages = "6:1--6:??",
month = feb,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2559948",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Feb 28 17:01:18 MST 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Kolaitis and Kopparty have shown that for any
first-order formula with parity quantifiers over the
language of graphs, there is a family of multivariate
polynomials of constant-degree that agree with the
formula on all but a $ 2^{- \Omega (n)} $-fraction of
the graphs with n vertices. The proof bounds the degree
of the polynomials by a tower of exponentials whose
height is the nesting depth of parity quantifiers in
the formula. We show that this tower-type dependence is
necessary. We build a family of formulas of depth $q$
whose approximating polynomials must have degree
bounded from below by a tower of exponentials of height
proportional to $q$. Our proof has two main parts.
First, we adapt and extend the results by Kolaitis and
Kopparty that describe the joint distribution of the
parities of the numbers of copies of small subgraphs in
a random graph to the setting of graphs of growing
size. Second, we analyze a variant of Karp's graph
canonical labeling algorithm and exploit its massive
parallelism to get a formula of low depth that defines
an almost canonical pre-order on a random graph.",
acknowledgement = ack-nhfb,
articleno = "6",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Schmidt:2014:UTD,
author = "Renate A. Schmidt and Dmitry Tishkovsky",
title = "Using tableau to decide description logics with full
role negation and identity",
journal = j-TOCL,
volume = "15",
number = "1",
pages = "7:1--7:??",
month = feb,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2559947",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Feb 28 17:01:18 MST 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "This article presents a tableau approach for deciding
expressive description logics with full role negation
and role identity. We consider the description logic
ALBO$^{id}$, which is ALC extended with the Boolean
role operators, inverse of roles, the identity role,
and includes full support for individuals and singleton
concepts. ALBO$^{id}$ is expressively equivalent to the
two-variable fragment of first-order logic with
equality and subsumes Boolean modal logic. In this
article, we define a sound, complete, and terminating
tableau calculus for ALBO$^{id}$ that provides the
basis for decision procedures for this logic and all
its sublogics. An important novelty of our approach is
the use of a generic unrestricted blocking mechanism.
Unrestricted blocking is based on equality reasoning
and a conceptually simple rule, which performs case
distinctions over the identity of individuals. The
blocking mechanism ties the proof of termination of
tableau derivations to the finite model property of
ALBO$^{id}$.",
acknowledgement = ack-nhfb,
articleno = "7",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Tan:2014:ETV,
author = "Tony Tan",
title = "Extending two-variable logic on data trees with order
on data values and its automata",
journal = j-TOCL,
volume = "15",
number = "1",
pages = "8:1--8:??",
month = feb,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2559945",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Feb 28 17:01:18 MST 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Data trees are trees in which each node, besides
carrying a label from a finite alphabet, also carries a
data value from an infinite domain. They have been used
as an abstraction model for reasoning tasks on XML and
verification. However, most existing approaches
consider the case where only equality test can be
performed on the data values. In this article we study
data trees in which the data values come from a
linearly ordered domain, and in addition to equality
test, we can test whether the data value in a node is
greater than the one in another node. We introduce an
automata model for them which we call ordered-data tree
automata (ODTA), provide its logical characterisation,
and prove that its non-emptiness problem is decidable
in 3-NE xpTime. We also show that the two-variable
logic on unranked data trees, studied by Bojanczyk et
al. [2009], corresponds precisely to a special subclass
of this automata model. Then we define a slightly
weaker version of ODTA, which we call weak ODTA, and
provide its logical characterisation. The complexity of
the non-emptiness problem drops to NP. However, a
number of existing formalisms and models studied in the
literature can be captured already by weak ODTA. We
also show that the definition of ODTA can be easily
modified, to the case where the data values come from a
tree-like partially ordered domain, such as strings.",
acknowledgement = ack-nhfb,
articleno = "8",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Chen:2014:CEP,
author = "Hubie Chen",
title = "On the complexity of existential positive queries",
journal = j-TOCL,
volume = "15",
number = "1",
pages = "9:1--9:??",
month = feb,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2559946",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Feb 28 17:01:18 MST 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We systematically investigate the complexity of model
checking the existential positive fragment of
first-order logic. In particular, for a set of
existential positive sentences, we consider model
checking where the sentence is restricted to fall into
the set; a natural question is then to classify which
sentence sets are tractable and which are intractable.
With respect to fixed-parameter tractability, we give a
general theorem that reduces this classification
question to the corresponding question for primitive
positive logic, for a variety of representations of
structures. This general theorem allows us to deduce
that an existential positive sentence set having
bounded arity is fixed-parameter tractable if and only
if each sentence is equivalent to one in
bounded-variable logic. We then use the lens of
classical complexity to study these fixed-parameter
tractable sentence sets. We show that such a set can be
NP-complete, and consider the length needed by a
translation from sentences in such a set to
bounded-variable logic; we prove superpolynomial lower
bounds on this length using the theory of
compilability, obtaining an interesting type of formula
size lower bound. Overall, the tools, concepts, and
results of this article set the stage for the future
consideration of the complexity of model checking on
more expressive logics.",
acknowledgement = ack-nhfb,
articleno = "9",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Zhang:2014:RCB,
author = "Lan Zhang and Ullrich Hustadt and Clare Dixon",
title = "A resolution calculus for the branching-time temporal
logic {CTL}",
journal = j-TOCL,
volume = "15",
number = "1",
pages = "10:1--10:??",
month = feb,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2529993",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Feb 28 17:01:18 MST 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The branching-time temporal logic CTL is useful for
specifying systems that change over time and involve
quantification over possible futures. Here we present a
resolution calculus for CTL that involves the
translation of formulae to a normal form and the
application of a number of resolution rules. We use
indices in the normal form to represent particular
paths and the application of the resolution rules is
restricted dependent on an ordering and selection
function to reduce the search space. We show that the
translation preserves satisfiability, the calculus is
sound, complete, and terminating, and consider the
complexity of the calculus.",
acknowledgement = ack-nhfb,
articleno = "10",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Asuncion:2014:PFO,
author = "Vernon Asuncion and Yan Zhang and Yi Zhou",
title = "Preferred First-Order Answer Set Programs",
journal = j-TOCL,
volume = "15",
number = "2",
pages = "11:1--11:??",
month = apr,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2579817",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon May 5 17:57:30 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In this article, we consider the issue of how
first-order answer set programs can be extended for
handling preference reasoning. To this end, we propose
a progression-based preference semantics for
first-order answer set programs while explicit
preference relations are presented. We study essential
properties of the proposed preferred answer set
semantics. To understand the expressiveness of
preferred first-order answer set programming, we
further specify a second-order logic representation
which precisely characterizes the progression-based
preference semantics.",
acknowledgement = ack-nhfb,
articleno = "11",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Son:2014:FNU,
author = "Tran Cao Son and Enrico Pontelli and Ngoc-Hieu Nguyen
and Chiaki Sakama",
title = "Formalizing Negotiations Using Logic Programming",
journal = j-TOCL,
volume = "15",
number = "2",
pages = "12:1--12:??",
month = apr,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2526270",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon May 5 17:57:30 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The article introduces a logical framework for
negotiation among dishonest agents. The framework
relies on the use of abductive logic programming as a
knowledge representation language for agents to deal
with incomplete information and preferences. The
article shows how intentionally false or inaccurate
information of agents can be encoded in the agents'
knowledge bases. Such disinformation can be effectively
used in the process of negotiation to have desired
outcomes by agents. The negotiation processes are
formulated under the answer set semantics of abductive
logic programming, and they enable the exploration of
various strategies that agents can employ in their
negotiation. A preliminary implementation has been
developed using the ASP-Prolog platform.",
acknowledgement = ack-nhfb,
articleno = "12",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Eisner:2014:SLW,
author = "Cindy Eisner and Dana Fisman and John Havlicek",
title = "Safety and Liveness, Weakness and Strength, and the
Underlying Topological Relations",
journal = j-TOCL,
volume = "15",
number = "2",
pages = "13:1--13:??",
month = apr,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2532440",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon May 5 17:57:30 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present a characterization that shows what it means
for a formula to be a weak or strong version of another
formula. We show that the weak version of a formula is
not the same as Alpern and Schneider's safety
component, but can be achieved by taking the closure in
the Cantor topology over an augmented alphabet in which
every formula is satisfiable. The resulting
characterization allows us to show that the set of
semantically weak formulas is exactly the set of
nonpathological safety formulas. Furthermore, we use
the characterization to show that the original versions
of the ieee standard temporal logics psl and sva are
broken, and we show that the source of the problem lies
in the semantics of the sere intersection and fusion
operators. Finally, we use the topological
characterization to show the internal consistency of
the alternative semantics adopted by the latest version
of the psl standard.",
acknowledgement = ack-nhfb,
articleno = "13",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Feng:2014:SBQ,
author = "Yuan Feng and Yuxin Deng and Mingsheng Ying",
title = "Symbolic Bisimulation for Quantum Processes",
journal = j-TOCL,
volume = "15",
number = "2",
pages = "14:1--14:??",
month = apr,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2579818",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon May 5 17:57:30 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "With the previous notions of bisimulation presented in
the literature, to check if two quantum processes are
bisimilar, we have to instantiate their free quantum
variables with arbitrary quantum states, and verify the
bisimilarity of the resulting configurations. This
makes checking bisimilarity infeasible from an
algorithmic point of view, because quantum states
constitute a continuum. In this article, we introduce a
symbolic operational semantics for quantum processes
directly at the quantum operation level, which allows
us to describe the bisimulation between quantum
processes without resorting to quantum states. We show
that the symbolic bisimulation defined here is
equivalent to the open bisimulation for quantum
processes in previous work, when strong bisimulations
are considered. An algorithm for checking symbolic
ground bisimilarity is presented. We also give a modal
characterisation for quantum bisimilarity based on an
extension of Hennessy--Milner logic to quantum
processes.",
acknowledgement = ack-nhfb,
articleno = "14",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bollig:2014:PWA,
author = "Benedikt Bollig and Paul Gastin and Benjamin Monmege
and Marc Zeitoun",
title = "Pebble Weighted Automata and Weighted Logics",
journal = j-TOCL,
volume = "15",
number = "2",
pages = "15:1--15:??",
month = apr,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2579819",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon May 5 17:57:30 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We introduce new classes of weighted automata on
words. Equipped with pebbles, they go beyond the class
of recognizable formal power series: they capture
weighted first-order logic enriched with a quantitative
version of transitive closure. In contrast to previous
work, this calculus allows for unrestricted use of
existential and universal quantifications over
positions of the input word. We actually consider both
two-way and one-way pebble weighted automata. The
latter class constrains the head of the automaton to
walk left-to-right, resetting it each time a pebble is
dropped. Such automata have already been considered in
the Boolean setting, in the context of data words. Our
main result states that two-way pebble weighted
automata, one-way pebble weighted automata, and our
weighted logic are expressively equivalent. We also
give new logical characterizations of standard
recognizable series.",
acknowledgement = ack-nhfb,
articleno = "15",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Chatterjee:2014:POS,
author = "Krishnendu Chatterjee and Laurent Doyen",
title = "Partial-Observation Stochastic Games: How to Win when
Belief Fails",
journal = j-TOCL,
volume = "15",
number = "2",
pages = "16:1--16:??",
month = apr,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2579821",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon May 5 17:57:30 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In two-player finite-state stochastic games of partial
observation on graphs, in every state of the graph, the
players simultaneously choose an action, and their
joint actions determine a probability distribution over
the successor states. The game is played for infinitely
many rounds and thus the players construct an infinite
path in the graph. We consider reachability objectives
where the first player tries to ensure a target state
to be visited almost-surely (i.e., with probability 1)
or positively (i.e., with positive probability), no
matter the strategy of the second player. We classify
such games according to the information and to the
power of randomization available to the players. On the
basis of information, the game can be one-sided with
either ( a ) player 1, or ( b ) player 2 having partial
observation (and the other player has perfect
observation), or two-sided with ( c ) both players
having partial observation. On the basis of
randomization, ( a ) the players may not be allowed to
use randomization (pure strategies), or ( b ) they may
choose a probability distribution over actions but the
actual random choice is external and not visible to the
player (actions invisible), or ( c ) they may use full
randomization. Our main results for pure strategies are
as follows: (1) For one-sided games with player 2
having perfect observation we show that (in contrast to
full randomized strategies) belief-based
(subset-construction based) strategies are not
sufficient, and we present an exponential upper bound
on memory both for almost-sure and positive winning
strategies; we show that the problem of deciding the
existence of almost-sure and positive winning
strategies for player 1 is EXPTIME-complete and present
symbolic algorithms that avoid the explicit exponential
construction. (2) For one-sided games with player 1
having perfect observation we show that nonelementary
memory is both necessary and sufficient for both
almost-sure and positive winning strategies. (3) We
show that for the general (two-sided) case
finite-memory strategies are sufficient for both
positive and almost-sure winning, and at least
nonelementary memory is required. We establish the
equivalence of the almost-sure winning problems for
pure strategies and for randomized strategies with
actions invisible. Our equivalence result exhibit
serious flaws in previous results of the literature: we
show a nonelementary memory lower bound for almost-sure
winning whereas an exponential upper bound was
previously claimed.",
acknowledgement = ack-nhfb,
articleno = "16",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Beckmann:2014:PGP,
author = "Arnold Beckmann and Pavel Pudl{\'a}k and Neil Thapen",
title = "Parity Games and Propositional Proofs",
journal = j-TOCL,
volume = "15",
number = "2",
pages = "17:1--17:??",
month = apr,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2579822",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon May 5 17:57:30 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A propositional proof system is weakly automatizable
if there is a polynomial time algorithm that separates
satisfiable formulas from formulas that have a short
refutation in the system, with respect to a given
length bound. We show that if the resolution proof
system is weakly automatizable, then parity games can
be decided in polynomial time. We give simple proofs
that the same holds for depth-1 propositional calculus
(where resolution has depth 0) with respect to mean
payoff and simple stochastic games. We define a new
type of combinatorial game and prove that resolution is
weakly automatizable if and only if one can separate,
by a set decidable in polynomial time, the games in
which the first player has a positional winning
strategy from the games in which the second player has
a positional winning strategy. Our main technique is to
show that a suitable weak bounded arithmetic theory
proves that both players in a game cannot
simultaneously have a winning strategy, and then to
translate this proof into propositional form.",
acknowledgement = ack-nhfb,
articleno = "17",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Molinaro:2014:SSS,
author = "Cristian Molinaro and Amy Sliva and V. S.
Subrahmanian",
title = "Super-Solutions: Succinctly Representing Solutions in
Abductive Annotated Probabilistic Temporal Logic",
journal = j-TOCL,
volume = "15",
number = "3",
pages = "18:1--18:??",
month = sep,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2627354",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Sep 8 19:06:46 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Annotated Probabilistic Temporal (APT) logic programs
are a form of logic programs that allow users to state
(or systems to automatically learn) rules of the form
``formula $G$ becomes true $ \Delta t$ time units after
formula $F$ became true with $l$ to $u$ \%
probability.'' In this article, we deal with abductive
reasoning in APT logic: given an APT logic program $
\Pi $, a set of formulas $H$ that can be ``added'' to $
\Pi $, and a (temporal) goal $g$, is there a subset $S$
of $H$ such that $ \Pi \cup S$ is consistent and
entails the goal $g$ ? In general, there are many
different solutions to the problem and some of them can
be highly repetitive, differing only in some
unimportant temporal aspects. We propose a compact
representation called super-solutions that succinctly
represent sets of such solutions. Super-solutions are
compact, but lossless representations of sets of such
solutions. We study the complexity of existence of
basic, super-, and maximal super-solutions as well as
check if a set is a solution\slash super-solution\slash
maximal super-solution. We then leverage a geometric
characterization of the problem to suggest a set of
pruning strategies and interesting properties that can
be leveraged to make the search of basic and
super-solutions more efficient. We propose correct
sequential algorithms to find solutions and
super-solutions. In addition, we develop parallel
algorithms to find basic and super-solutions.",
acknowledgement = ack-nhfb,
articleno = "18",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Creignou:2014:CCL,
author = "Nadia Creignou and Uwe Egly and Johannes Schmidt",
title = "Complexity Classifications for Logic-Based
Argumentation",
journal = j-TOCL,
volume = "15",
number = "3",
pages = "19:1--19:??",
month = sep,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2629421",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Sep 8 19:06:46 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We consider logic-based argumentation in which an
argument is a pair $ (\Phi, \alpha) $, where the
support $ \Phi $ is a minimal consistent set of
formulae taken from a given knowledge base (usually
denoted by $ \Delta $) that entails the claim $ \alpha
$ (a formula). We study the complexity of three central
problems in argumentation: the existence of a support $
\Phi \subseteq \Delta $ , the verification of a
support, and the relevance problem (given $ \psi $, is
there a support $ \Phi $ such that $ \psi \in \Phi $
?). When arguments are given in the full language of
propositional logic, these problems are computationally
costly tasks: the verification problem is DP-complete;
the others are $ \Sigma^p_2$-complete. We study these
problems in Schaefer's famous framework where the
considered propositional formulae are in generalized
conjunctive normal form. This means that formulae are
conjunctions of constraints built upon a fixed finite
set of Boolean relations $ \Gamma $ (the constraint
language). We show that according to the properties of
this language $ \Gamma $, deciding whether there exists
a support for a claim in a given knowledge base is
either polynomial, NP-complete, coNP-complete, or $
\Sigma^p_2$-complete. We present a dichotomous
classification, P or DP-complete, for the verification
problem and a trichotomous classification for the
relevance problem into either polynomial, NP-complete,
or $ \Sigma^p_2$-complete. These last two
classifications are obtained by means of algebraic
tools.",
acknowledgement = ack-nhfb,
articleno = "19",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Aschinger:2014:LLC,
author = "Markus Aschinger and Conrad Drescher and Georg Gottlob
and Heribert Vollmer",
title = "{LoCo} --- a Logic for Configuration Problems",
journal = j-TOCL,
volume = "15",
number = "3",
pages = "20:1--20:??",
month = sep,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2629454",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Sep 8 19:06:46 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In this work, we present LoCo, a fragment of classical
first-order logic carefully tailored for expressing
technical product configuration problems. The core
feature of LoCo is that the number of components used
in configurations does not have to be finitely bounded
explicitly, but instead is bounded implicitly through
the axioms. Computing configurations is equivalent to
the task of model finding. We present the language,
related algorithms, and complexity results as well as a
prototypical implementation via answer set
programming.",
acknowledgement = ack-nhfb,
articleno = "20",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Simmons:2014:SF,
author = "Robert J. Simmons",
title = "Structural Focalization",
journal = j-TOCL,
volume = "15",
number = "3",
pages = "21:1--21:??",
month = sep,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2629678",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Sep 8 19:06:46 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Focusing, introduced by Jean-Marc Andreoli in the
context of classical linear logic [Andreoli 1992],
defines a normal form for sequent calculus derivations
that cuts down on the number of possible derivations by
eagerly applying invertible rules and grouping
sequences of non-invertible rules. A focused sequent
calculus is defined relative to some nonfocused sequent
calculus; focalization is the property that every
nonfocused derivation can be transformed into a focused
derivation. In this article, we present a focused
sequent calculus for propositional intuitionistic logic
and prove the focalization property relative to a
standard presentation of propositional intuitionistic
logic. Compared to existing approaches, the proof is
quite concise, depending only on the internal soundness
and completeness of the focused logic. In turn, both of
these properties can be established (and mechanically
verified) by structural induction in the style of
Pfenning's structural cut elimination without the need
for any tedious and repetitious invertibility lemmas.
The proof of cut admissibility for the focused system,
which establishes internal soundness, is not
particularly novel. The proof of identity expansion,
which establishes internal completeness, is a major
contribution of this work.",
acknowledgement = ack-nhfb,
articleno = "21",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Ying:2014:MCL,
author = "Mingsheng Ying and Yangjia Li and Nengkun Yu and Yuan
Feng",
title = "Model-Checking Linear-Time Properties of Quantum
Systems",
journal = j-TOCL,
volume = "15",
number = "3",
pages = "22:1--22:??",
month = sep,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2629680",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Sep 8 19:06:46 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We define a formal framework for reasoning about
linear-time properties of quantum systems in which
quantum automata are employed in the modeling of
systems and certain (closed) subspaces of state Hilbert
spaces are used as the atomic propositions about the
behavior of systems. We provide an algorithm for
verifying invariants of quantum automata. Then, an
automata-based model-checking technique is generalized
for the verification of safety properties recognizable
by reversible automata and $ \omega $-properties
recognizable by reversible B{\"u}chi automata.",
acknowledgement = ack-nhfb,
articleno = "22",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Poza:2014:CRS,
author = "Mar{\'\i}a Poza and C{\'e}sar Dom{\'\i}nguez and
J{\'o}nathan Heras and Julio Rubio",
title = "A Certified Reduction Strategy for Homological Image
Processing",
journal = j-TOCL,
volume = "15",
number = "3",
pages = "23:1--23:??",
month = sep,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2630789",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Sep 8 19:06:46 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The analysis of digital images using homological
procedures is an outstanding topic in the area of
Computational Algebraic Topology. In this article, we
describe a certified reduction strategy to deal with
digital images, but one preserving their homological
properties. We stress both the advantages of our
approach (mainly, the formalization of the mathematics
allowing us to verify the correctness of algorithms)
and some limitations (related to the performance of the
running systems inside proof assistants). The drawbacks
are overcome using techniques that provide an
integration of computation and deduction. Our driving
application is a problem in bioinformatics, where the
accuracy and reliability of computations are specially
requested.",
acknowledgement = ack-nhfb,
articleno = "23",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Carayol:2014:RAI,
author = "Arnaud Carayol and Axel Haddad and Olivier Serre",
title = "Randomization in Automata on Infinite Trees",
journal = j-TOCL,
volume = "15",
number = "3",
pages = "24:1--24:??",
month = sep,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2629336",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Sep 8 19:06:46 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study finite automata running over infinite binary
trees. A run of such an automaton over an input tree is
a tree labeled by control states of the automaton: the
labeling is built in a top-down fashion and should be
consistent with the transitions of the automaton. A
branch in a run is accepting if the $ \omega $-word
obtained by reading the states along the branch
satisfies some acceptance condition (typically an $
\omega $-regular condition such as a B{\"u}chi or a
parity condition). Finally, a tree is accepted by the
automaton if there exists a run over this tree in which
every branch is accepting. In this article, we consider
two relaxations of this definition, introducing a
qualitative aspect. First, we relax the notion of
accepting run by allowing a negligible set (in the
sense of measure theory) of nonaccepting branches. In
this qualitative setting, a tree is accepted by the
automaton if there exists a run over this tree in which
almost every branch is accepting. This leads to a new
class of tree languages, qualitative tree languages.
This class enjoys many good properties: closure under
union and intersection (but not under complement), and
emptiness is decidable in polynomial time. A dual
class, positive tree languages, is defined by requiring
that an accepting run contains a non-negligeable set of
branches. The second relaxation is to replace the
existential quantification (a tree is accepted if there
exists some accepting run over the input tree) with a
probabilistic quantification (a tree is accepted if
almost every run over the input tree is accepting). For
the run, we may use either classical acceptance or
qualitative acceptance. In particular, for the latter,
we exhibit a tight connection with partial observation
Markov decision processes. Moreover, if we additionally
restrict operation to the B{\"u}chi condition, we show
that it leads to a class of probabilistic automata on
infinite trees enjoying a decidable emptiness problem.
To our knowledge, this is the first positive result for
a class of probabilistic automaton over infinite
trees.",
acknowledgement = ack-nhfb,
articleno = "24",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Artale:2014:CTC,
author = "Alessandro Artale and Roman Kontchakov and Vladislav
Ryzhikov and Michael Zakharyaschev",
title = "A Cookbook for Temporal Conceptual Data Modelling with
Description Logics",
journal = j-TOCL,
volume = "15",
number = "3",
pages = "25:1--25:??",
month = sep,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2629565",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Sep 8 19:06:46 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We design temporal description logics (TDLs) suitable
for reasoning about temporal conceptual data models and
investigate their computational complexity. Our
formalisms are based on DL-Lite logics with three types
of concept inclusions (ranging from atomic concept
inclusions and disjointness to the full Booleans), as
well as cardinality constraints and role inclusions.
The logics are interpreted over the Cartesian products
of object domains and the flow of time (Z, {$<$}),
satisfying the constant domain assumption. Concept and
role inclusions of the TBox hold at all moments of time
(globally), and data assertions of the ABox hold at
specified moments of time. To express temporal
constraints of conceptual data models, the languages
are equipped with flexible and rigid roles, standard
future and past temporal operators on concepts, and
operators ``always'' and ``sometime'' on roles. The
most expressive of our TDLs (which can capture lifespan
cardinalities and either qualitative or quantitative
evolution constraints) turns out to be undecidable.
However, by omitting some of the temporal operators on
concepts/roles or by restricting the form of concept
inclusions, we construct logics whose complexity ranges
between NL ogSpace and PSpace. These positive results
are obtained by reduction to various clausal fragments
of propositional temporal logic, which opens a way to
employ propositional or first-order temporal provers
for reasoning about temporal data models.",
acknowledgement = ack-nhfb,
articleno = "25",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Goller:2014:RPR,
author = "Stefan G{\"o}ller and Anthony Widjaja Lin",
title = "Refining the Process Rewrite Systems Hierarchy via
Ground Tree Rewrite Systems",
journal = j-TOCL,
volume = "15",
number = "4",
pages = "26:1--26:??",
month = sep,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2629679",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Sep 13 07:31:07 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In his seminal paper, Mayr introduced the well-known
process rewrite systems (PRS) hierarchy, which contains
many well-studied classes of infinite-state systems
including pushdown systems (PDS), Petri nets, and
PA-processes. A separate development in the term
rewriting community introduced the notion of ground
tree rewrite systems (GTRS), which is a model that
strictly extends PDS while still enjoying desirable
decidable properties. There have been striking
similarities between the verification problems that
have been shown decidable (and undecidable) over GTRS
and over models in the PRS hierarchy such as PA and PAD
processes. It is open to what extent PRS and GTRS are
connected in terms of their expressive power. In this
article, we pinpoint the exact connection between GTRS
and models in the PRS hierarchy in terms of their
expressive power with respect to strong, weak, and
branching bisimulation. Among others, this connection
allows us to give new insights into the decidability
results for subclasses of PRS, such as simpler proofs
of known decidability results of verifications problems
on PAD.",
acknowledgement = ack-nhfb,
articleno = "26",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Boker:2014:TSA,
author = "Udi Boker and Krishnendu Chatterjee and Thomas A.
Henzinger and Orna Kupferman",
title = "Temporal Specifications with Accumulative Values",
journal = j-TOCL,
volume = "15",
number = "4",
pages = "27:1--27:??",
month = sep,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2629686",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Sep 13 07:31:07 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Recently, there has been an effort to add quantitative
objectives to formal verification and synthesis. We
introduce and investigate the extension of temporal
logics with quantitative atomic assertions. At the
heart of quantitative objectives lies the accumulation
of values along a computation. It is often the
accumulated sum, as with energy objectives, or the
accumulated average, as with mean-payoff objectives. We
investigate the extension of temporal logics with the
prefix-accumulation assertions Sum( v ) {$>$}= c and
Avg( v ) {$>$}= c, where v is a numeric (or Boolean)
variable of the system, c is a constant rational
number, and Sum( v ) and Avg( v ) denote the
accumulated sum and average of the values of v from the
beginning of the computation up to the current point in
time. We also allow the path-accumulation assertions
LimInfAvg( v ){$>$}= c and LimSupAvg( v ){$>$}= c,
referring to the average value along an entire infinite
computation. We study the border of decidability for
such quantitative extensions of various temporal
logics. In particular, we show that extending the
fragment of CTL that has only the EX, EF, AX, and AG
temporal modalities with both prefix-accumulation
assertions, or extending LTL with both
path-accumulation assertions, results in temporal
logics whose model-checking problem is decidable.
Moreover, the prefix-accumulation assertions may be
generalized with ``controlled accumulation,'' allowing,
for example, to specify constraints on the average
waiting time between a request and a grant. On the
negative side, we show that this branching-time logic
is, in a sense, the maximal logic with one or both of
the prefix-accumulation assertions that permits a
decidable model-checking procedure. Extending a
temporal logic that has the EG or EU modalities, such
as CTL or LTL, makes the problem undecidable.",
acknowledgement = ack-nhfb,
articleno = "27",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Komosinski:2014:IEA,
author = "Maciej Komosinski and Adam Kups and Dorota
Leszczy{\'n}ska-Jasion and Mariusz Urba{\'n}ski",
title = "Identifying Efficient Abductive Hypotheses Using
Multicriteria Dominance Relation",
journal = j-TOCL,
volume = "15",
number = "4",
pages = "28:1--28:??",
month = sep,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2629669",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Sep 13 07:31:07 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In this article, results of the automation of an
abductive procedure are reported. This work is a
continuation of our earlier research [Komosinski et al.
2012], where a general scheme of the procedure has been
proposed. Here, a more advanced system developed to
generate and evaluate abductive hypotheses is
introduced. Abductive hypotheses have been generated by
the implementation of the synthetic tableau method.
Prior to the evaluation, the set of hypotheses has
undergone several reduction phases. To assess
usefulness of abductive hypotheses in the reduced set,
several criteria have been employed. The evaluation of
efficiency of the hypotheses has been provided by the
multicriteria dominance relation. To comprehend the
abductive procedure and the evaluation process more
extensively, analyses have been conducted on a number
of artificially generated abductive problems.",
acknowledgement = ack-nhfb,
articleno = "28",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Frigeri:2014:FTL,
author = "Achille Frigeri and Liliana Pasquale and Paola
Spoletini",
title = "Fuzzy Time in Linear Temporal Logic",
journal = j-TOCL,
volume = "15",
number = "4",
pages = "30:1--30:??",
month = sep,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2629606",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Sep 13 07:31:07 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In the past years, the adoption of adaptive systems
has increased in many fields of computer science, such
as databases and software engineering. These systems
are able to automatically react to events by collecting
information from the external environment and
generating new events. However, the collection of data
is often hampered by uncertainty and vagueness. The
decision-making mechanism used to produce a reaction is
also imprecise and cannot be evaluated in a crisp way,
as it depends on vague temporal constraints expressed
by humans. Logic has been extensively used as an
abstraction to express vagueness in the satisfaction of
system properties, as well as to enrich existing
modeling formalisms. However, existing attempts to
fuzzify the temporal modalities still have some
limitations. Existing fuzzy temporal languages are
generally obtained from classical temporal logic by
replacing classical connectives or propositions with
their fuzzy counterparts. Hence, these languages do not
allow us to represent temporal properties, such as
``almost always'' and ``soon,'' in which the notion of
time is inherently fuzzy. To overcome these
limitations, we propose a temporal framework,
fuzzy-time temporal logic (FTL), to express vagueness
on time. This framework formally defines a set of fuzzy
temporal modalities that can be customized by choosing
a specific semantics for the connectives. The semantics
of the language is sound, and the introduced modalities
respect a set of mutual relations. We also prove that
under the assumption that all events are crisp, FTL
reduces to linear temporal logic (LTL). Moreover, for
some of the possible fuzzy interpretations of the
connectives, we identify adequate sets of temporal
operators, from which it is possible to derive all of
the other ones.",
acknowledgement = ack-nhfb,
articleno = "30",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Schellhorn:2014:SCP,
author = "Gerhard Schellhorn and John Derrick and Heike
Wehrheim",
title = "A Sound and Complete Proof Technique for
Linearizability of Concurrent Data Structures",
journal = j-TOCL,
volume = "15",
number = "4",
pages = "31:1--31:??",
month = sep,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2629496",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Sep 13 07:31:07 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Efficient implementations of data structures such as
queues, stacks or hash-tables allow for concurrent
access by many processes at the same time. To increase
concurrency, these algorithms often completely dispose
with locking, or only lock small parts of the
structure. Linearizability is the standard correctness
criterion for such a scenario-where a concurrent object
is linearizable if all of its operations appear to take
effect instantaneously some time between their
invocation and return. The potential concurrent access
to the shared data structure tremendously increases the
complexity of the verification problem, and thus
current proof techniques for showing linearizability
are all tailored to specific types of data structures.
In previous work, we have shown how simulation-based
proof conditions for linearizability can be used to
verify a number of subtle concurrent algorithms. In
this article, we now show that conditions based on
backward simulation can be used to show linearizability
of every linearizable algorithm, that is, we show that
our proof technique is both sound and complete. We
exemplify our approach by a linearizability proof of a
concurrent queue, introduced in Herlihy and Wing's
landmark paper on linearizability. Except for their
manual proof, none of the numerous other approaches
have successfully treated this queue. Our approach is
supported by a full mechanisation: both the
linearizability proofs for case studies like the queue,
and the proofs of soundness and completeness have been
carried out with an interactive prover, which is KIV.",
acknowledgement = ack-nhfb,
articleno = "31",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Riguzzi:2014:TEL,
author = "Fabrizio Riguzzi and Terrance Swift",
title = "Terminating Evaluation of Logic Programs with Finite
Three-Valued Models",
journal = j-TOCL,
volume = "15",
number = "4",
pages = "32:1--32:??",
month = sep,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2629337",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Sep 13 07:31:07 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "As evaluation methods for logic programs have become
more sophisticated, the classes of programs for which
termination can be guaranteed have expanded. From the
perspective of ar set programs that include function
symbols, recent work has identified classes for which
grounding routines can terminate either on the entire
program [Calimeri et al. 2008] or on suitable queries
[Baselice et al. 2009]. From the perspective of
tabling, it has long been known that a tabling
technique called subgoal abstraction provides good
termination properties for definite programs [Tamaki
and Sato 1986], and this result was recently extended
to stratified programs via the class of bounded
term-size programs [Riguzzi and Swift 2013]. In this
article, we provide a formal definition of tabling with
subgoal abstraction resulting in the SLG$_{SA}$
algorithm. Moreover, we discuss a declarative
characterization of the queries and programs for which
SLG$_{SA}$ terminates. We call this class strongly
bounded term-size programs and show its equivalence to
programs with finite well-founded models. For normal
programs, strongly bounded term-size programs strictly
includes the finitely ground programs of Calimeri et
al. [2008]. SLG$_{SA}$ has an asymptotic complexity on
strongly bounded term-size programs equal to the best
known and produces a residual program that can be sent
to an answer set programming system. Finally, we
describe the implementation of subgoal abstraction
within the SLG-WAM of XSB and provide performance
results.",
acknowledgement = ack-nhfb,
articleno = "32",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Zanardini:2014:IFS,
author = "Damiano Zanardini and Samir Genaim",
title = "Inference of Field-Sensitive Reachability and
Cyclicity",
journal = j-TOCL,
volume = "15",
number = "4",
pages = "33:1--33:??",
month = sep,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2629478",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Sep 13 07:31:07 MDT 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In heap-based languages, knowing that a variable x
points to an acyclic data structure is useful for
analyzing termination. This information guarantees that
the depth of the data structure to which x points is
greater than the depth of the structure pointed to by
x. fld, and allows bounding the number of iterations of
a loop that traverses the data structure on fld. In
general, proving termination needs acyclicity, unless
program-specific or nonautomated reasoning is
performed. However, recent work could prove that
certain loops terminate even without inferring
acyclicity, because they traverse data structures
``acyclically.'' Consider a double-linked list: if it
is possible to demonstrate that every cycle involves
both the ``next'' and the ``prev'' field, then a
traversal on ``next'' terminates since no cycle will be
traversed completely. This article develops a static
analysis inferring field-sensitive reachability and
cyclicity information, which is more general than
existing approaches. Propositional formul{\ae} are
computed, which describe which fields may or may not be
traversed by paths in the heap. Consider a tree with
edges ``left'' and ``right'' to the left and right
subtrees, and ``parent'' to the parent node:
termination of a loop traversing leaf-up cannot be
guaranteed by state-of-the-art analyses. Instead,
propositional formul{\ae} computed by this analysis
indicate that cycles must traverse ``parent'' and at
least one between ``left'' and ``right'': termination
is guaranteed, as no cycle is traversed completely.
This work defines the necessary abstract domains and
builds an abstract semantics on them. A prototypical
implementation provides the expected result on relevant
examples.",
acknowledgement = ack-nhfb,
articleno = "33",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Mogavero:2014:RAS,
author = "Fabio Mogavero and Aniello Murano and Giuseppe Perelli
and Moshe Y. Vardi",
title = "Reasoning About Strategies: On the Model-Checking
Problem",
journal = j-TOCL,
volume = "15",
number = "4",
pages = "34:1--34:??",
month = nov,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2631917",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Nov 24 15:22:24 MST 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In open systems verification, to formally check for
reliability, one needs an appropriate formalism to
model the interaction between agents and express the
correctness of the system no matter how the environment
behaves. An important contribution in this context is
given by modal logics for strategic ability, in the
setting of multiagent games, such as Atl, Atl*, and
the like. Recently, Chatterjee, Henzinger, and Piterman
introduced Strategy Logic, which we denote here by
CHP-Sl, with the aim of getting a powerful framework
for reasoning explicitly about strategies. CHP-Sl is
obtained by using first-order quantifications over
strategies and has been investigated in the very
specific setting of two-agents turned-based games,
where a nonelementary model-checking algorithm has been
provided. While CHP-Sl is a very expressive logic, we
claim that it does not fully capture the strategic
aspects of multiagent systems. In this article, we
introduce and study a more general strategy logic,
denoted Sl, for reasoning about strategies in
multiagent concurrent games. As a key aspect,
strategies in Sl are not intrinsically glued to a
specific agent, but an explicit binding operator allows
an agent to bind to a strategy variable. This allows
agents to share strategies or reuse one previously
adopted. We prove that Sl strictly includes CHP-Sl,
while maintaining a decidable model-checking problem.
In particular, the algorithm we propose is
computationally not harder than the best one known for
CHP-Sl. Moreover, we prove that such a problem for Sl
is NonElementary. This negative result has spurred us
to investigate syntactic fragments of Sl, strictly
subsuming Atl*, with the hope of obtaining an
elementary model-checking problem. Among others, we
introduce and study the sublogics Sl[ng], Sl[bg], and
Sl[1g]. They encompass formulas in a special prenex
normal form having, respectively, nested temporal
goals, Boolean combinations of goals, and, a single
goal at a time. Intuitively, for a goal, we mean a
sequence of bindings, one for each agent, followed by
an Ltl formula. We prove that the model-checking
problem for Sl[1g] is 2ExpTime-complete, thus not
harder than the one for Atl*. In contrast, Sl[ng] turns
out to be NonElementary-hard, strengthening the
corresponding result for Sl. Regarding Sl[bg], we show
that it includes CHP-Sl and its model-checking is
decidable with a 2ExpTimelower-bound. It is worth
enlightening that to achieve the positive results about
S l[1g], we introduce a fundamental property of the
semantics of this logic, called behavioral, which
allows to strongly simplify the reasoning about
strategies. Indeed, in a nonbehavioral logic such as
Sl[bg] and the subsuming ones, to satisfy a formula,
one has to take into account that a move of an agent,
at a given moment of a play, may depend on the moves
taken by any agent in another counterfactual play.",
acknowledgement = ack-nhfb,
articleno = "34",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bonchi:2014:GTB,
author = "Filippo Bonchi and Fabio Gadducci and Giacoma
Valentina Monreale",
title = "A General Theory of Barbs, Contexts, and Labels",
journal = j-TOCL,
volume = "15",
number = "4",
pages = "35:1--35:??",
month = nov,
year = "2014",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2631916",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Nov 24 15:22:24 MST 2014",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Barbed bisimilarity is a widely used behavioral
equivalence for interactive systems: given a set of
predicates (denoted ``barbs'' and representing basic
observations on states) and a set of contexts
(representing the possible execution environments), two
systems are deemed to be equivalent if they verify the
same barbs whenever inserted inside any of the chosen
contexts. Despite its flexibility and expressiveness,
this definition of equivalence is unsatisfactory
because often the quantification is over an infinite
set of contexts, thus making barbed bisimilarity very
hard to be verified. Should a labeled operational
semantics be available, more efficient observational
equivalences might be adopted. To this end, a series of
techniques has been proposed to derive labeled
transition systems (LTSs) from unlabeled ones, the main
example being Leifer and Milner's theory of reactive
systems. The underlying intuition is that labels should
be the ``minimal'' contexts that allow for a reduction
step to be performed. However, minimality is difficult
to asses, whereas the set of ``intuitively'' correct
labels is often easily devised by the ingenuity of the
researcher. This article introduces a framework that
characterizes (weak) barbed bisimilarity via LTSs whose
labels are (not necessarily minimal) contexts.
Differently from previous proposals, our theory does
not depend on the way the labeled transitions are built
but instead relies on a simple set-theoretical
presentation for identifying those properties such an
LTS should verify to (1) capture the barbed
bisimilarities of the underlying system and (2) ensure
that such bisimilarities are congruences. Furthermore,
we adopt suitable proof techniques to make feasible the
verification of such properties. To provide a test-bed
for our formalism, we instantiate it by addressing the
semantics of the Mobile Ambients calculus, recasting
its barbed bisimilarities via label-based behavioral
equivalences.",
acknowledgement = ack-nhfb,
articleno = "35",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Halamish:2015:MDL,
author = "Shulamit Halamish and Orna Kupferman",
title = "Minimizing Deterministic Lattice Automata",
journal = j-TOCL,
volume = "16",
number = "1",
pages = "1:1--1:??",
month = mar,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2631915",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Mar 24 17:04:26 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Traditional automata accept or reject their input and
are therefore Boolean. In contrast, weighted automata
map each word to a value from a semiring over a large
domain. The special case of lattice automata, in which
the semiring is a finite lattice, has interesting
theoretical properties as well as applications in
formal methods. A minimal deterministic automaton
captures the combinatorial nature and complexity of a
formal language. Deterministic automata are used in
runtime monitoring, pattern recognition, and modeling
systems. Thus, the minimization problem for
deterministic automata is of great interest, both
theoretically and in practice. For deterministic
traditional automata on finite words, a minimization
algorithm, based on the Myhill--Nerode right congruence
on the set of words, generates in polynomial time a
canonical minimal deterministic automaton. A polynomial
algorithm is known also for deterministic weighted
automata over the tropical semiring. For general
deterministic weighted automata, the problem of
minimization is open. In this article, we study
minimization of deterministic lattice automata. We show
that it is impossible to define a right congruence in
the context of lattices, and that no canonical minimal
automaton exists. Consequently, the minimization
problem is much more complicated, and we prove that it
is NP-complete. As good news, we show that while right
congruence fails already for finite lattices that are
fully ordered, for this setting we are able to combine
a finite number of right congruences and generate a
minimal deterministic automaton in polynomial time.",
acknowledgement = ack-nhfb,
articleno = "1",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Crafa:2015:LCB,
author = "Silvia Crafa and Francesco Ranzato",
title = "Logical Characterizations of Behavioral Relations on
Transition Systems of Probability Distributions",
journal = j-TOCL,
volume = "16",
number = "1",
pages = "2:1--2:??",
month = mar,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2641566",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Mar 6 10:01:34 MST 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Probabilistic nondeterministic processes are commonly
modeled as probabilistic LTSs (PLTSs). A number of
logical characterizations of the main behavioral
relations on PLTSs have been studied. In particular,
Parma and Segala [2007] and Hermanns et al. [2011]
define a probabilistic Hennessy--Milner logic
interpreted over probability distributions, whose
corresponding logical equivalence/preorder when
restricted to Dirac distributions coincides with
standard bisimulation/simulation between the states of
a PLTS. This result is here extended by studying the
full logical equivalence/preorder between (possibly
non-Dirac) distributions in terms of a notion of
bisimulation/simulation defined on an LTS whose states
are distributions (dLTS). We show that the well-known
spectrum of behavioral relations on nonprobabilistic
LTSs as well as their corresponding logical
characterizations in terms of Hennessy--Milner logic
scales to the probabilistic setting when considering
dLTSs.",
acknowledgement = ack-nhfb,
articleno = "2",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Tao:2015:CFS,
author = "Jia Tao and Giora Slutzki and Vasant Honavar",
title = "A Conceptual Framework for Secrecy-preserving
Reasoning in Knowledge Bases",
journal = j-TOCL,
volume = "16",
number = "1",
pages = "3:1--3:??",
month = mar,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2637477",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Mar 6 10:01:34 MST 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In many applications, Knowledge Bases (KBs) contain
confidential or private information (secrets). The KB
should be able to use this secret information in its
reasoning process but in answering user queries care
must be exercised so that secrets are not revealed to
unauthorized users. We consider this problem under the
Open World Assumption (OWA) in a setting with multiple
querying agents $ M_1 $, \ldots{}, $ M_m $ that can
pose queries against the KB K and selectively share
answers that they receive from K with one or more other
querying agents. We assume that for each $ M_i $, the
KB has a prespecified set of secrets $ S_i $ that need
to be protected from $ M_i $. Communication between
querying agents is modeled by a communication graph, a
directed graph with self-loops. We introduce a general
framework and propose an approach to secrecy-preserving
query answering based on sound and complete proof
systems. The idea is to hide the truthful answer from a
querying agent $ M_i $ by feigning ignorance without
lying (i.e., to provide the answer `Unknown' to a query
$q$ if it needs to be protected). Under the OWA, a
querying agent cannot distinguish between the case that
$q$ is being protected (for reasons of secrecy) and the
case that it cannot be inferred from K. In the
pre-query stage we compute a set of envelopes $ E_1$,
\ldots{}, $ E_m$ (restricted to a finite subset of the
set of formulae that are entailed by K) so that $ S_i
\subseteq E_i$, and a query \alpha posed by agent $
M_i$ can be answered truthfully whenever $ \alpha \not
\in E_i$ and $ \isonot \alpha \not \in E_i$. After the
pre-query stage, the envelope is updated as needed. We
illustrate this approach with two simple cases: the
Propositional Horn KBs and the Description Logic AL
KBs.",
acknowledgement = ack-nhfb,
articleno = "3",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Biscaia:2015:DAS,
author = "M. Biscaia and D. Henriques and P. Mateus",
title = "Decidability of Approximate {Skolem} Problem and
Applications to Logical Verification of Dynamical
Properties of {Markov} Chains",
journal = j-TOCL,
volume = "16",
number = "1",
pages = "4:1--4:??",
month = mar,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2666772",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Mar 6 10:01:34 MST 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "When studying probabilistic dynamical systems,
temporal logic has typically been used to analyze path
properties. Recently, there has been some interest in
analyzing the dynamical evolution of state
probabilities of these systems. In this article, we
show that verifying linear temporal properties
concerning the state evolution induced by a Markov
chain is equivalent to the decidability of the Skolem
problem --- a long-standing open problem in Number
Theory. However, from a practical point of view,
usually it is enough to check properties up to some
acceptable error bound $ \epsilon $. We show that an
approximate version of the Skolem problem is decidable,
and that it can be applied to verify, up to arbitrarily
small $ \epsilon $, linear temporal properties of the
state evolution induced by a Markov chain.",
acknowledgement = ack-nhfb,
articleno = "4",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Ciabattoni:2015:TPO,
author = "Agata Ciabattoni and Ori Lahav and Lara Spendier and
Anna Zamansky",
title = "Taming Paraconsistent (and Other) Logics: an
Algorithmic Approach",
journal = j-TOCL,
volume = "16",
number = "1",
pages = "5:1--5:??",
month = mar,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2661636",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Mar 6 10:01:34 MST 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We develop a fully algorithmic approach to ``taming''
logics expressed Hilbert style, that is, reformulating
them in terms of analytic sequent calculi and useful
semantics. Our approach applies to Hilbert calculi
extending the positive fragment of propositional
classical logic with axioms of a certain general form
that contain new unary connectives. Our work
encompasses various results already obtained for
specific logics. It can be applied to new logics, as
well as to known logics for which an analytic calculus
or a useful semantics has so far not been available. A
Prolog implementation of the method is described.",
acknowledgement = ack-nhfb,
articleno = "5",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Avni:2015:PWC,
author = "Guy Avni and Orna Kupferman",
title = "Parameterized Weighted Containment",
journal = j-TOCL,
volume = "16",
number = "1",
pages = "6:1--6:??",
month = mar,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2665076",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Mar 6 10:01:34 MST 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Partially specified systems and specifications are
used in formal methods such as stepwise design and
query checking. Existing methods consider a setting in
which systems and their correctness are Boolean. In
recent years, there has been growing interest and need
for quantitative formal methods, where systems may be
weighted and specifications may be multivalued.
Weighted automata, which map input words to a numerical
value, play a key role in quantitative reasoning.
Technically, every transition in a weighted automaton A
has a cost, and the value A assigns to a finite word w
is the sum of the costs on the transitions traversed
along the most expensive accepting run of A on w. We
study parameterized weighted containment: given three
weighted automata A, B, and C, with B being partial,
the goal is to find an assignment to the missing costs
in B so that we end up with B ' for which B '{$<$}= C,
where {$<$}= is the weighted counterpart of
containment. We also consider a one-sided version of
the problem, where only A or only C is given in
addition to B, and the goal is to find a minimal
assignment with which A {$<$}= B ' or, respectively, a
maximal one with which B ' {$<$}= C. We argue that both
problems are useful in stepwise design of weighted
systems as well as approximated minimization of
weighted automata. We show that when the automata are
deterministic, we can solve the problems in polynomial
time. Our solution is based on the observation that the
set of legal assignments to k missing costs forms a k
-dimensional polytope. The technical challenge is to
find an assignment in polynomial time even though the
polytope is defined by means of exponentially many
inequalities. We do so by developing a
divide-and-conquer algorithm based on a separation
oracle for polytopes. For nondeterministic automata,
the weighted setting is much more complex, and in fact
even nonparameterized containment is undecidable. We
are able to show positive results for variants of the
problems, where containment is replaced by
simulation.",
acknowledgement = ack-nhfb,
articleno = "6",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Fontaine:2015:WIH,
author = "Ga{\"e}lle Fontaine",
title = "Why Is It Hard to Obtain a Dichotomy for Consistent
Query Answering?",
journal = j-TOCL,
volume = "16",
number = "1",
pages = "7:1--7:??",
month = mar,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2699912",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Mar 24 17:04:26 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A database may for various reasons become inconsistent
with respect to a given set of integrity constraints.
In the late 1990s, the formal approach of consistent
query answering was proposed in order to query such
databases. Since then, a lot of efforts have been spent
to classify the complexity of consistent query
answering under various classes of constraints. It is
known that for the most common constraints and queries,
the problem is in coNP and might be coNP-hard, yet
several relevant tractable classes have been
identified. Additionally, the results that emerged
suggested that given a set of key constraints and a
conjunctive query, the problem of consistent query
answering is either in PTime or is coNP-complete.
However, despite all the work, as of today this
dichotomy remains a conjecture. The main contribution
of this article is to explain why it appears so
difficult to obtain a dichotomy result in the setting
of consistent query answering. Namely, we prove that
such a dichotomy with respect to common classes of
constraints and queries is harder to achieve than a
dichotomy for the constraint satisfaction problem,
which is a famous open problem since the 1990s.",
acknowledgement = ack-nhfb,
articleno = "7",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Ferrari:2015:EDD,
author = "Mauro Ferrari and Camillo Fiorentini and Guido
Fiorino",
title = "An Evaluation-Driven Decision Procedure for {G3i}",
journal = j-TOCL,
volume = "16",
number = "1",
pages = "8:1--8:??",
month = mar,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2660770",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Mar 24 17:04:26 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "It is well known that G3i, the sequent calculus for
intuitionistic propositional logic where weakening and
contraction are absorbed into the rules, is not
terminating. Indeed, due to the contraction in the rule
for left implication, the na{\"\i}ve goal-oriented
proof-search strategy, consisting in applying the rules
of the calculus bottom up until possible, can generate
branches of infinite length. The usual solution to this
problem is to support the proof-search procedure with a
loop checking mechanism that prevents the generation of
infinite branches by storing and analyzing some
information regarding the branch under development. In
this article, we propose a new technique based on
evaluation functions. An evaluation function is a
lightweight computational mechanism that, analyzing
only the current goal of the proof search, allows one
to drive the application of rules to guarantee
termination and to avoid useless backtracking. We
describe an evaluation-driven proof-search procedure
that given a sequent $\sigma$ returns either a
G3i-derivation of $\sigma$ or a countermodel for
$\sigma$. We prove that such a procedure is terminating
and correct, and that the depth of the G3i-trees
generated during proof search is quadratic in the size
of $\sigma$. Finally, we discuss the overhead time
introduced by evaluation functions in the proof-search
procedure.",
acknowledgement = ack-nhfb,
articleno = "8",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Goller:2015:CDM,
author = "Stefan G{\"o}ller and Jean-Christoph Jung and Markus
Lohrey",
title = "The Complexity of Decomposing Modal and First-Order
Theories",
journal = j-TOCL,
volume = "16",
number = "1",
pages = "9:1--9:??",
month = mar,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2699918",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Tue Mar 24 17:04:26 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study the satisfiability problem of the logic $ K^2
= K \times K $ --- the two-dimensional variant of
unimodal logic, where models are restricted to
asynchronous products of two Kripke frames. Gabbay and
Shehtman proved in 1998 that this problem is decidable
in a tower of exponentials. So far, the best-known
lower bound is NEXP-hardness shown by Marx and
Mikul{\'a}s in 2001. Our first main result closes this
complexity gap. We show that satisfiability in $ K^2 $
is nonelementary. More precisely, we prove that it is
$k$-NEXP-complete, where $k$ is the switching depth
(the minimal modal rank among the two dimensions) of
the input formula, hereby solving a conjecture of Marx
and Mikul{\'a}s. Using our lower-bound technique also
allows us to derive nonelementary lower bounds for the
two-dimensional modal logics $ K4 \times K$ and $ S5_2
\times K$, for which only elementary lower bounds were
previously known. Moreover, we apply our technique to
prove nonelementary lower bounds for the sizes of
Feferman-Vaught decompositions with respect to product
for any decomposable logic that is at least as
expressive as unimodal $K$, generalizing a recent
result by the first author and Lin. For the
three-variable fragment FO$^3$ of first-order logic, we
obtain the following two immediate corollaries: the
size of Feferman-Vaught decompositions with respect to
disjoint sum are inherently nonelementary, and
equivalent formulas in Gaifman normal form are
inherently nonelementary. Our second main result
consists in providing effective elementary (more
precisely, doubly exponential) upper bounds for the
two-variable fragment FO$^2$ of first-order logic both
for Feferman-Vaught decompositions and for equivalent
formulas in Gaifman normal form.",
acknowledgement = ack-nhfb,
articleno = "9",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Simonsen:2015:CRS,
author = "Jakob Grue Simonsen",
title = "A Confluent Rewriting System Having No Computable,
One-Step, Normalizing Strategy",
journal = j-TOCL,
volume = "16",
number = "2",
pages = "10:1--10:??",
month = feb,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2699917",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Mar 6 10:01:37 MST 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A full and finitely generated Church--Rosser term
rewriting system is presented that has no computable
one-step, normalizing strategy; the system is both
left- and right-linear. The result provides a negative
answer to a question posed by Kennaway in 1989: Number
10 on the List of Open Problems in Rewriting.",
acknowledgement = ack-nhfb,
articleno = "10",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Skarlatidis:2015:PEC,
author = "Anastasios Skarlatidis and Georgios Paliouras and
Alexander Artikis and George A. Vouros",
title = "Probabilistic Event Calculus for Event Recognition",
journal = j-TOCL,
volume = "16",
number = "2",
pages = "11:1--11:??",
month = feb,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2699916",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Mar 6 10:01:37 MST 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Symbolic event recognition systems have been
successfully applied to a variety of application
domains, extracting useful information in the form of
events, allowing experts or other systems to monitor
and respond when significant events are recognised. In
a typical event recognition application, however, these
systems often have to deal with a significant amount of
uncertainty. In this article, we address the issue of
uncertainty in logic-based event recognition by
extending the Event Calculus with probabilistic
reasoning. Markov logic networks are a natural
candidate for our logic-based formalism. However, the
temporal semantics of the Event Calculus introduce a
number of challenges for the proposed model. We show
how and under what assumptions we can overcome these
problems. Additionally, we study how probabilistic
modelling changes the behaviour of the formalism,
affecting its key property-the inertia of fluents.
Furthermore, we demonstrate the advantages of the
probabilistic Event Calculus through examples and
experiments in the domain of activity recognition,
using a publicly available dataset for video
surveillance.",
acknowledgement = ack-nhfb,
articleno = "11",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Sebastiani:2015:OMT,
author = "Roberto Sebastiani and Silvia Tomasi",
title = "Optimization Modulo Theories with Linear Rational
Costs",
journal = j-TOCL,
volume = "16",
number = "2",
pages = "12:1--12:??",
month = feb,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2699915",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Mar 6 10:01:37 MST 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In the contexts of automated reasoning (AR) and formal
verification (FV), important decision problems are
effectively encoded into Satisfiability Modulo Theories
(SMT). In the last decade, efficient SMT solvers have
been developed for several theories of practical
interest (e.g., linear arithmetic, arrays, and bit
vectors). Surprisingly, little work has been done to
extend SMT to deal with optimization problems; in
particular, we are not aware of any previous work on
SMT solvers able to produce solutions that minimize
cost functions over arithmetical variables. This is
unfortunate, since some problems of interest require
this functionality. In the work described in this
article we start filling this gap. We present and
discuss two general procedures for leveraging SMT to
handle the minimization of linear rational cost
functions, combining SMT with standard minimization
techniques. We have implemented the procedures within
the MathSAT SMT solver. Due to the absence of
competitors in the AR, FV, and SMT domains, we have
experimentally evaluated our implementation against
state-of-the-art tools for the domain of Linear
Generalized Disjunctive Programming (LGDP), which is
closest in spirit to our domain, on sets of problems
that have been previously proposed as benchmarks for
the latter tools. The results show that our tool is
very competitive with, and often outperforms, these
tools on these problems, clearly demonstrating the
potential of the approach.",
acknowledgement = ack-nhfb,
articleno = "12",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Jouannaud:2015:NHO,
author = "Jean-Pierre Jouannaud and Albert Rubio",
title = "Normal Higher-Order Termination",
journal = j-TOCL,
volume = "16",
number = "2",
pages = "13:1--13:??",
month = mar,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2699913",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 7 09:04:46 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We extend the termination proof methods based on
reduction orderings to higher-order rewriting systems
based on higher-order pattern matching. We accommodate,
on the one hand, a weakly polymorphic, algebraic
extension of Church's simply typed $ \lambda $-calculus
and, on the other hand, any use of eta, as a reduction,
as an expansion, or as an equation. The user's rules
may be of any type in this type system, either a base,
functional, or weakly polymorphic type.",
acknowledgement = ack-nhfb,
articleno = "13",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Felgenhauer:2015:LSP,
author = "Bertram Felgenhauer and Aart Middeldorp and Harald
Zankl and Vincent {Van Oostrom}",
title = "Layer Systems for Proving Confluence",
journal = j-TOCL,
volume = "16",
number = "2",
pages = "14:1--14:??",
month = mar,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2710017",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 7 09:04:46 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We introduce layer systems for proving generalizations
of the modularity of confluence for first-order rewrite
systems. Layer systems specify how terms can be divided
into layers. We establish structural conditions on
those systems that imply confluence. Our abstract
framework covers known results like modularity,
many-sorted persistence, layer-preservation, and
currying. We present a counterexample to an extension
of persistence to order-sorted rewriting and derive new
sufficient conditions for the extension to hold. All
our proofs are constructive.",
acknowledgement = ack-nhfb,
articleno = "14",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Demri:2015:TVS,
author = "St{\'e}phane Demri and Morgan Deters",
title = "Two-Variable Separation Logic and Its Inner Circle",
journal = j-TOCL,
volume = "16",
number = "2",
pages = "15:1--15:??",
month = mar,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2724711",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 7 09:04:46 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Separation logic is a well-known assertion language
for Hoare-style proof systems. We show that first-order
separation logic with a unique record field restricted
to two quantified variables and no program variables is
undecidable. This is among the smallest fragments of
separation logic known to be undecidable, and this
contrasts with the decidability of two-variable
first-order logic. We also investigate its restriction
by dropping the magic wand connective, known to be
decidable with nonelementary complexity, and we show
that the satisfiability problem with only two
quantified variables is not yet elementary recursive.
Furthermore, we establish insightful and concrete
relationships between two-variable separation logic and
propositional interval temporal logic (PITL), data
logics, and modal logics, providing an inner circle of
closely related logics.",
acknowledgement = ack-nhfb,
articleno = "15",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Geneves:2015:EDC,
author = "Pierre Genev{\`e}s and Nabil Laya{\"\i}da and Alan
Schmitt and Nils Gesbert",
title = "Efficiently Deciding $ \mu $-Calculus with Converse
over Finite Trees",
journal = j-TOCL,
volume = "16",
number = "2",
pages = "16:1--16:??",
month = mar,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2724712",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 7 09:04:46 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present a sound and complete satisfiability-testing
algorithm and its effective implementation for an
alternation-free modal $ \mu $-calculus with converse,
where formulas are cycle-free and are interpreted over
finite ordered trees. The time complexity of the
satisfiability-testing algorithm is $ 2^{O(n)}$ in
terms of formula size n. The algorithm is implemented
using symbolic techniques (BDD). We present crucial
implementation techniques and heuristics that we used
to make the algorithm as fast as possible in practice.
Our implementation is available online and can be used
to solve logical formulas of significant size and
practical value. We illustrate this in the setting of
XML trees.",
acknowledgement = ack-nhfb,
articleno = "16",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Kopczynski:2015:VHF,
author = "Eryk Kopczy{\'n}ski and Tony Tan",
title = "On the Variable Hierarchy of First-Order Spectra",
journal = j-TOCL,
volume = "16",
number = "2",
pages = "17:1--17:??",
month = mar,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2733376",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 7 09:04:46 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The spectrum of a first-order logic sentence is the
set of natural numbers that are cardinalities of its
finite models. In this article, we study the hierarchy
of first-order spectra based on the number of
variables. It has been conjectured that it collapses to
three variables. We show the opposite: it forms an
infinite hierarchy. However, despite the fact that more
variables can express more spectra, we show that to
establish whether the class of first-order spectra is
closed under complement, it is sufficient to consider
sentences using only three variables and binary
relations.",
acknowledgement = ack-nhfb,
articleno = "17",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Kraus:2015:HHH,
author = "Nicolai Kraus and Christian Sattler",
title = "Higher Homotopies in a Hierarchy of Univalent
Universes",
journal = j-TOCL,
volume = "16",
number = "2",
pages = "18:1--18:??",
month = mar,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2729979",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 7 09:04:46 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "For Martin-L{\"o}f type theory with a hierarchy $ U_0
$: $ U_1 $: $ U_2 $: \ldots{} of univalent universes,
we show that $ U_n $ is not an $n$-type. Our
construction also solves the problem of finding a type
that strictly has some high truncation level without
using higher inductive types. In particular, $ U_n$ is
such a type if we restrict it to $n$-types. We have
fully formalized and verified our results within the
dependently typed language and proof assistant Agda.",
acknowledgement = ack-nhfb,
articleno = "18",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Novakovic:2015:PSC,
author = "Novak Novakovi{\'c} and Lutz Stra{\ss}burger",
title = "On the Power of Substitution in the Calculus of
Structures",
journal = j-TOCL,
volume = "16",
number = "3",
pages = "19:1--19:??",
month = jul,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2701424",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 7 09:04:47 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "There are two contributions in this article. First, we
give a direct proof of the known fact that Frege
systems with substitution can be p-simulated by the
calculus of structures (CoS) extended with the
substitution rule. This is done without referring to
the p-equivalence of extended Frege systems and Frege
systems with substitution. Second, we then show that
the cut-free CoS with substitution is p-equivalent to
the cut-free CoS with extension.",
acknowledgement = ack-nhfb,
articleno = "19",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Lazic:2015:NCB,
author = "Ranko Lazi{\'c} and Sylvain Schmitz",
title = "Nonelementary Complexities for Branching {VASS},
{MELL}, and Extensions",
journal = j-TOCL,
volume = "16",
number = "3",
pages = "20:1--20:??",
month = jul,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2733375",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 7 09:04:47 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study the complexity of reachability problems on
branching extensions of vector addition systems, which
allows us to derive new non-elementary complexity
bounds for fragments and variants of propositional
linear logic. We show that provability in the
multiplicative exponential fragment is T ower-hard
already in the affine case-and hence non-elementary. We
match this lower bound for the full propositional
affine linear logic, proving its Tower-completeness. We
also show that provability in propositional contractive
linear logic is Ackermann-complete.",
acknowledgement = ack-nhfb,
articleno = "20",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Berkholz:2015:BQD,
author = "Christoph Berkholz and Andreas Krebs and Oleg
Verbitsky",
title = "Bounds for the Quantifier Depth in Finite-Variable
Logics: Alternation Hierarchy",
journal = j-TOCL,
volume = "16",
number = "3",
pages = "21:1--21:??",
month = jul,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2732409",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 7 09:04:47 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Given two structures $G$ and $H$ distinguishable in
FO$^k$ (first-order logic with $k$ variables), let $
A^k(G, H)$ denote the minimum alternation depth of a
FO$^k$ formula distinguishing $G$ from $H$. Let $
A^k(n)$ be the maximum value of $ A^k(G, H)$ over
$n$-element structures. We prove the strictness of the
quantifier alternation hierarchy of FO$^2$ in a strong
quantitative form, namely $ A^2 (n) > n / 8 - 2$, which
is tight up to a constant factor. For each $ k \geq 2$,
it holds that $ A^k(n) > \log_{k + 1} n - 2$ even over
colored trees, which is also tight up to a constant
factor if $ k \geq 3$. For $ k \geq 3$, the last lower
bound holds also over uncolored trees, whereas the
alternation hierarchy of FO$^2$ collapses even over all
uncolored graphs. We also show examples of colored
graphs $G$ and $H$ on $n$ vertices that can be
distinguished in FO$^2$ much more succinctly if the
alternation number is increased just by one: Whereas in
$ \Sigma_i$ it is possible to distinguish $G$ from $H$
with bounded quantifier depth, in $ \Pi_i$ this
requires quantifier depth $ \Omega (n^2)$. The
quadratic lower bound is best possible here because, if
$G$ and $H$ can be distinguished in FO$^k$ with $i$
quantifier alternations, this can be done with
quantifier depth $ n^{2 k - 2} + 1$ and the same number
of alternations.",
acknowledgement = ack-nhfb,
articleno = "21",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Fazzinga:2015:CPA,
author = "Bettina Fazzinga and Sergio Flesca and Francesco
Parisi",
title = "On the Complexity of Probabilistic Abstract
Argumentation Frameworks",
journal = j-TOCL,
volume = "16",
number = "3",
pages = "22:1--22:??",
month = jul,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2749463",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 7 09:04:47 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Probabilistic abstract argumentation combines Dung's
abstract argumentation framework with probability
theory in order to model uncertainty in argumentation.
In this setting, we address the fundamental problem of
computing the probability that a set of arguments is an
extension according to a given semantics. We focus on
the most popular semantics (i.e., admissible, stable,
complete, grounded, preferred, ideal-set, ideal, stage,
and semistable) and show the following dichotomy
result: computing the probability that a set of
arguments is an extension is either FP or FP$^{\#
P}$-complete depending on the semantics adopted. Our
polynomial-time results are particularly interesting,
as they hold for some semantics for which no
polynomial-time technique was known so far.",
acknowledgement = ack-nhfb,
articleno = "22",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Lumsdaine:2015:LUM,
author = "Peter Lefanu Lumsdaine and Michael A. Warren",
title = "The Local Universes Model: an Overlooked Coherence
Construction for Dependent Type Theories",
journal = j-TOCL,
volume = "16",
number = "3",
pages = "23:1--23:??",
month = jul,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2754931",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 7 09:04:47 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present a new coherence theorem for comprehension
categories, providing strict models of dependent type
theory with all standard constructors, including
dependent products, dependent sums, identity types, and
other inductive types. Precisely, we take as input a
``weak model'': a comprehension category, equipped with
structure corresponding to the desired logical
constructions. We assume throughout that the base
category is close to locally Cartesian closed:
specifically, that products and certain exponentials
exist. Beyond this, we require only that the logical
structure should be weakly stable -a pure existence
statement, not involving any specific choice of
structure, weaker than standard categorical
Beck--Chevalley conditions, and holding in the now
standard homotopy-theoretic models of type theory.
Given such a comprehension category, we construct an
equivalent split one whose logical structure is
strictly stable under reindexing. This yields an
interpretation of type theory with the chosen
constructors. The model is adapted from Voevodsky's use
of universes for coherence, and at the level of
fibrations is a classical construction of Giraud. It
may be viewed in terms of local universes or delayed
substitutions.",
acknowledgement = ack-nhfb,
articleno = "23",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Heule:2015:SAC,
author = "Marijn J. H. Heule and Stefan Szeider",
title = "A {SAT} Approach to Clique-Width",
journal = j-TOCL,
volume = "16",
number = "3",
pages = "24:1--24:??",
month = jul,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2736696",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 7 09:04:47 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Clique-width is a graph invariant that has been widely
studied in combinatorics and computational logic.
Computing the clique-width of a graph is an intricate
problem, because the exact clique-width is not known
even for very small graphs. We present a new method for
computing clique-width via an encoding to propositional
satisfiability (SAT), which is then evaluated by a SAT
solver. Our encoding is based on a reformulation of
clique-width in terms of partitions that utilizes an
efficient encoding of cardinality constraints. Our
SAT-based method is the first to discover the exact
clique-width of various small graphs, including famous
named graphs from the literature as well as random
graphs of various density. With our method, we
determined the smallest graphs that require a small
predescribed clique-width. We further show how our
method can be modified to compute the linear
clique-width of graphs, a variant of clique-width that
has recently received considerable attention. In an
appendix, we provide certificates for tight upper
bounds for the clique-width and linear clique-width of
famous named graphs.",
acknowledgement = ack-nhfb,
articleno = "24",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Benerecetti:2015:RAS,
author = "Massimo Benerecetti and Fabio Mogavero and Aniello
Murano",
title = "Reasoning About Substructures and Games",
journal = j-TOCL,
volume = "16",
number = "3",
pages = "25:1--25:??",
month = jul,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2757286",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 7 09:04:47 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Many decision problems in formal verification and
design can be suitably formulated in game-theoretic
terms. This is the case for the model checking of open
and closed systems and both controller and reactive
synthesis. Interpreted in this context, these problems
require one to find a strategy (i.e., a plan) to force
the system to fulfill some desired goal, no matter what
the opponent (e.g., the environment) does. A strategy
essentially constrains the possible behaviors of the
system to those that are compatible with the decisions
dictated by the plan itself. Therefore, finding a
strategy to meet some goal basically reduces to
identifying a portion of the model of interest (i.e.,
one of its substructures) that satisfies that goal. In
this view, the ability to reason about substructures
becomes a crucial aspect for several fundamental
problems. In this article, we present and study a new
branching-time temporal logic, called Substructure
Temporal Logic (STL * for short), whose distinctive
feature is to allow for quantifying over the possible
substructure of a given structure. The logic is
obtained by adding four new temporal-like operators to
CTL *, whose interpretation is given relative to the
partial order induced by a suitable substructure
relation. STL * turns out to be very expressive and
allows one to capture in a very natural way many
well-known problems, such as module checking, reactive
synthesis, and reasoning about games in a wide sense. A
formal account of the model-theoretic properties of the
new logic and results about (un)decidability and
complexity of related decision problems are also
provided.",
acknowledgement = ack-nhfb,
articleno = "25",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Asperti:2015:CCF,
author = "Andrea Asperti",
title = "Computational Complexity Via Finite Types",
journal = j-TOCL,
volume = "16",
number = "3",
pages = "26:1--26:??",
month = jul,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2764906",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 7 09:04:47 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We address computational complexity writing
polymorphic functions between finite types (i.e., types
with a finite number of canonical elements), expressing
costs in terms of the cardinality of these types. This
allows us to rediscover, in a more syntactical setting,
the known result that the different levels in the
hierarchy of higher-order primitive recursive functions
(G{\"o}del system $T$), when interpreted over finite
structures, precisely capture basic complexity classes:
functions of rank 1 characterize LOGSPACE, rank 2
PTIME, rank 3 PSPACE, rank 4 EXPTIME =
DTIME(2$^{poly}$), and so on.",
acknowledgement = ack-nhfb,
articleno = "26",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Hampson:2015:UPB,
author = "Christopher Hampson and Agi Kurucz",
title = "Undecidable Propositional Bimodal Logics and
One-Variable First-Order Linear Temporal Logics with
Counting",
journal = j-TOCL,
volume = "16",
number = "3",
pages = "27:1--27:??",
month = jul,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2757285",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Aug 7 09:04:47 MDT 2015",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "First-order temporal logics are notorious for their
bad computational behavior. It is known that even the
two-variable monadic fragment is highly undecidable
over various linear timelines, and over branching time
even one-variable fragments might be undecidable.
However, there have been several attempts at finding
well-behaved fragments of first-order temporal logics
and related temporal description logics, mostly either
by restricting the available quantifier patterns or by
considering sub-Boolean languages. Here we analyze
seemingly ``mild'' extensions of decidable one-variable
fragments with counting capabilities, interpreted in
models with constant, decreasing, and expanding
first-order domains. We show that over most classes of
linear orders, these logics are (sometimes highly)
undecidable, even without constant and function
symbols, and with the sole temporal operator
``eventually.'' We establish connections with bimodal
logics over 2D product structures having linear and
``difference'' (inequality) component relations and
prove our results in this bimodal setting. We show a
general result saying that satisfiability over many
classes of bimodal models with commuting ``unbounded''
linear and difference relations is undecidable. As a
byproduct, we also obtain new examples of finitely
axiomatizable but Kripke incomplete bimodal logics. Our
results generalize similar lower bounds on bimodal
logics over products of two linear relations, and our
proof methods are quite different from the known proofs
of these results. Unlike previous proofs that first
``diagonally encode'' an infinite grid and then use
reductions of tiling or Turing machine problems, here
we make direct use of the grid-like structure of
product frames and obtain lower-complexity bounds by
reductions of counter (Minsky) machine problems.
Representing counter machine runs apparently requires
less control over neighboring grid points than tilings
or Turing machine runs, and so this technique is
possibly more versatile, even if one component of the
underlying product structures is ``close to'' being the
universal relation.",
acknowledgement = ack-nhfb,
articleno = "27",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Filmus:2015:SSS,
author = "Yuval Filmus and Massimo Lauria and Mladen Miksa and
Jakob Nordstr{\"o}m and Marc Vinyals",
title = "From Small Space to Small Width in Resolution",
journal = j-TOCL,
volume = "16",
number = "4",
pages = "28:1--28:??",
month = nov,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2746339",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In 2003, Atserias and Dalmau resolved a major open
question about the resolution proof system by
establishing that the space complexity of a Conjunctive
Normal Form (CNF) formula is always an upper bound on
the width needed to refute the formula. Their proof is
beautiful but uses a nonconstructive argument based on
Ehrenfeucht-Fra{\"\i}ss{\'e} games. We give an
alternative, more explicit, proof that works by simple
syntactic manipulations of resolution refutations. As a
by-product, we develop a ``black-box'' technique for
proving space lower bounds via a ``static'' complexity
measure that works against any resolution
refutation-previous techniques have been inherently
adaptive. We conclude by showing that the related
question for polynomial calculus (i.e., whether space
is an upper bound on degree) seems unlikely to be
resolvable by similar methods.",
acknowledgement = ack-nhfb,
articleno = "28",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Cranen:2015:AFL,
author = "Sjoerd Cranen and Maciej Gazda and Wieger Wesselink
and Tim A. C. Willemse",
title = "Abstraction in Fixpoint Logic",
journal = j-TOCL,
volume = "16",
number = "4",
pages = "29:1--29:??",
month = nov,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2740964",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present a theory of abstraction for the framework
of parameterised Boolean equation systems, a
first-order fixpoint logic. Parameterised Boolean
equation systems can be used to solve a variety of
problems in verification. We study the capabilities of
the abstraction theory by comparing it to an
abstraction theory for Generalised Kripke modal
Transition Systems (GTSs). We show that for model
checking the modal $\mu$-calculus, our abstractions can
be exponentially more succinct than GTSs and our theory
is as complete as the GTS framework for
abstraction. Furthermore, we investigate the
completeness of our theory irrespective of the encoded
decision problem. We illustrate the potential of our
theory through case studies using the first-order modal
$\mu$-calculus and a real-time extension thereof,
conducted using a prototype implementation of a new
syntactic transformation for parameterised Boolean
equation systems.",
acknowledgement = ack-nhfb,
articleno = "29",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Furusawa:2015:CDA,
author = "Hitoshi Furusawa and Georg Struth",
title = "Concurrent Dynamic Algebra",
journal = j-TOCL,
volume = "16",
number = "4",
pages = "30:1--30:??",
month = nov,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2785967",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We reconstruct Peleg's concurrent dynamic logic in the
context of modal Kleene algebras. We explore the
algebraic structure of its multirelational semantics
and develop an axiomatization of concurrent dynamic
algebras from that basis. In this context, sequential
composition is not associative. It interacts with
parallel composition through a weak distributivity law.
The modal operators of concurrent dynamic algebra are
obtained from abstract axioms for domain and antidomain
operators; the Kleene star is modelled as a least
fixpoint. Algebraic variants of Peleg's axioms are
shown to be derivable in these algebras, and their
soundness is proved relative to the multirelational
model. Additional results include iteration principles
for the Kleene star and a refutation of variants of
Segerberg's axiom in the multirelational setting. The
most important results have been verified formally with
Isabelle/HOL.",
acknowledgement = ack-nhfb,
articleno = "30",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Wang:2015:DLO,
author = "Zhe Wang and Kewen Wang and Rodney Topor",
title = "{DL-Lite} Ontology Revision Based on An Alternative
Semantic Characterization",
journal = j-TOCL,
volume = "16",
number = "4",
pages = "31:1--31:??",
month = nov,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2786759",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Ontology engineering and maintenance require
(semi-)automated ontology change operations. Intensive
research has been conducted on TBox and ABox changes in
description logics (DLs), and various change operators
have been proposed in the literature. Existing
operators largely fall into two categories:
syntax-based and model-based. While each approach has
its advantages and disadvantages, an important topic
that has rarely been explored is how to achieve a
balance between syntax-based and model-based
approaches. Also, most existing operators are specially
designed for either TBox change or ABox change, and
cannot handle the general ontology revision task-given
a DL knowledge base (KB, a pair consisting of a TBox
and an ABox), how to revise it by a set of TBox and
ABox axioms ( i.e., a new DL KB). In this article, we
introduce an alternative structure for DL-Lite, called
a featured interpretation, and show that featured
models provide a finite and tight characterization to
the classical semantics of DL-Lite. A key issue for
defining a change operator is the so-called
expressibility, that is, whether a set of models (or
featured models here) is axiomatizable in DLs. It is
indeed much easier to obtain expressibility results for
featured models than for classical DL models. As a
result, the new semantics determined by featured models
provides a method for defining and studying various
changes of DL-Lite KBs that involve both TBoxes and
ABoxes. To demonstrate the usefulness of the new
semantic characterization in ontology change, we define
two revision operators for DL-Lite KBs using featured
models and study their properties. In particular, we
show that our two operators both satisfy AGM
postulates. We show that the complexity of our
revisions is $\Pi^P_2$-complete, that is, on the same
level as major revision operators in propositional
logic, which further justifies the feasibility of our
revision approach for DL-Lite. Also, we develop
algorithms for these DL-Lite revisions.",
acknowledgement = ack-nhfb,
articleno = "31",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Schwartz:2015:DRS,
author = "Daniel G. Schwartz",
title = "Dynamic Reasoning Systems",
journal = j-TOCL,
volume = "16",
number = "4",
pages = "32:1--32:??",
month = nov,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2798727",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A dynamic reasoning system (DRS) is an adaptation of a
conventional formal logical system that explicitly
portrays reasoning as a temporal activity, with each
extralogical input to the system and each inference
rule application being viewed as occurring at a
distinct timestep. Every DRS incorporates some
well-defined logic together with a controller that
serves to guide the reasoning process in response to
user inputs. Logics are generic, whereas controllers
are application specific. Every controller does,
nonetheless, provide an algorithm for nonmonotonic
belief revision. The general notion of a DRS comprises
a framework within which one can formulate the logic
and algorithms for a given application and prove that
the algorithms are correct, that is, that they serve to
(1) derive all salient information and (2) preserve the
consistency of the belief set. This article illustrates
the idea with ordinary first-order predicate calculus,
suitably modified for the present purpose, and two
examples. The latter example revisits some classic
nonmonotonic reasoning puzzles (Opus the Penguin, Nixon
Diamond) and shows how these can be resolved in the
context of a DRS, using an expanded version of
first-order logic that incorporates typed predicate
symbols. All concepts are rigorously defined and
effectively computable, thereby providing the
foundation for a future software implementation.",
acknowledgement = ack-nhfb,
articleno = "32",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Marchioni:2015:LGL,
author = "Enrico Marchioni and Michael Wooldridge",
title = "{Lukasiewicz} Games: a Logic-Based Approach to
Quantitative Strategic Interactions",
journal = j-TOCL,
volume = "16",
number = "4",
pages = "33:1--33:??",
month = nov,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2783436",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Boolean games provide a simple, compact, and
theoretically attractive abstract model for studying
multiagent interactions in settings where players will
act strategically in an attempt to achieve individual
goals. A standard critique of Boolean games, however,
is that the strictly dichotomous nature of the
preference relations induced by Boolean goals
inevitably trivialises the nature of such strategic
interactions: a player is assumed to be indifferent
between all outcomes that satisfy her goal, and
indifferent between all outcomes that do not satisfy
her goal. While various proposals have been made to
overcome this limitation, many of these proposals
require the inclusion of nonlogical structures into
games to capture nondichotomous preferences. In this
article, we introduce Lukasiewicz games, which overcome
this limitation by allowing goals to be specified using
Lukasiewicz logics. By expressing goals as formulae of
Lukasiewicz logics, we can express a much richer class
of utility functions for players than is possible using
classical Boolean logic: we can express every
continuous piecewise linear polynomial function with
rational coefficients over [0, 1]$^n$ as well as their
finite-valued restrictions over {0, 1/ k, ..., ( k ---
1)/ k, 1}$^n$. We thus obtain a representation of
nondichotomous preference structures within a purely
logical framework. After introducing the formal
framework of Lukasiewicz games, we present a number of
detailed worked examples to illustrate the framework,
and then investigate some of their theoretical
properties. In particular, we present a logical
characterisation of the existence of Nash equilibria in
finite and infinite Lukasiewicz games. We conclude by
briefly discussing issues of computational
complexity.",
acknowledgement = ack-nhfb,
articleno = "33",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Friedmann:2015:RBI,
author = "Oliver Friedmann and Felix Klaedtke and Martin Lange",
title = "{Ramsey}-Based Inclusion Checking for Visibly Pushdown
Automata",
journal = j-TOCL,
volume = "16",
number = "4",
pages = "34:1--34:??",
month = nov,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2774221",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Checking whether one formal language is included in
another is important in many verification tasks. In
this article, we provide solutions for checking the
inclusion of languages given by visibly pushdown
automata over both finite and infinite words. Visibly
pushdown automata are a richer automaton model than the
classical finite-state automata, which allows one, for
example, to reason about the nesting of procedure calls
in the executions of recursive imperative programs. The
presented solutions do not rely on explicit automaton
constructions for determinization and complementation.
Instead, they are more direct and generalize the
so-called Ramsey-based inclusion-checking algorithms,
which apply to classical finite-state automata and
proved to be effective there to visibly pushdown
automata. We also experimentally evaluate these
algorithms, demonstrating the virtues of avoiding
explicit determinization and complementation
constructions.",
acknowledgement = ack-nhfb,
articleno = "34",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Kramer:2015:LII,
author = "Simon Kramer",
title = "Logic of Intuitionistic Interactive Proofs (Formal
Theory of Perfect Knowledge Transfer)",
journal = j-TOCL,
volume = "16",
number = "4",
pages = "35:1--35:??",
month = nov,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2811263",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We produce a decidable super-intuitionistic normal
modal logic of internalised intuitionistic (and thus
disjunctive and monotonic) interactive proofs (LIiP)
from an existing classical counterpart of classical
monotonic non-disjunctive interactive proofs (LiP).
Intuitionistic interactive proofs effect a durable
epistemic impact in the possibly adversarial
communication medium CM (which is imagined as a
distinguished agent) and only in that, that consists in
the permanent induction of the perfect and thus
disjunctive knowledge of their proof goal by means of
CM's knowledge of the proof: If CM knew my proof then
CM would persistently and also disjunctively know that
my proof goal is true. So intuitionistic interactive
proofs effect a lasting transfer of disjunctive
propositional knowledge (disjunctively knowable facts)
in the communication medium of multi-agent distributed
systems via the transmission of certain individual
knowledge (knowable intuitionistic proofs). Our
(necessarily) CM-centred notion of proof is also a
disjunctive explicit refinement of KD45-belief, and
yields also such a refinement of standard S5-knowledge.
Monotonicity but not communality is a commonality of
LiP, LIiP, and their internalised notions of proof. As
a side-effect, we offer a short internalised proof of
the Disjunction Property of Intuitionistic Logic
(originally proved by G{\"o}del).",
acknowledgement = ack-nhfb,
articleno = "35",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Carayol:2015:ERA,
author = "Arnaud Carayol and Axel Haddad and Olivier Serre",
title = "Erratum for {``Randomization in Automata on Infinite
Trees''}",
journal = j-TOCL,
volume = "16",
number = "4",
pages = "36:1--36:??",
month = nov,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2824254",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
acknowledgement = ack-nhfb,
articleno = "36",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Platzer:2015:DGL,
author = "Andr{\'e} Platzer",
title = "Differential Game Logic",
journal = j-TOCL,
volume = "17",
number = "1",
pages = "1:1--1:??",
month = dec,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2817824",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Differential game logic (dG L ) is a logic for
specifying and verifying properties of hybrid games,
i.e., games that combine discrete, continuous, and
adversarial dynamics. Unlike hybrid systems, hybrid
games allow choices in the system dynamics to be
resolved adversarially by different players with
different objectives. The logic dG L can be used to
study the existence of winning strategies for such
hybrid games, i.e., ways of resolving the player's
choices in some way so that he wins by achieving his
objective for all choices of the opponent. Hybrid games
are determined, i.e., from each state, one player has a
winning strategy, yet computing their winning regions
may take transfinitely many steps. The logic dG L,
nevertheless, has a sound and complete axiomatization
relative to any expressive logic. Separating axioms are
identified that distinguish hybrid games from hybrid
systems. Finally, dG L is proved to be strictly more
expressive than the corresponding logic of hybrid
systems by characterizing the expressiveness of both.",
acknowledgement = ack-nhfb,
articleno = "1",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Michaliszyn:2015:DEM,
author = "Jakub Michaliszyn and Jan Otop and Emanuel
Kiero{\'n}ski",
title = "On the Decidability of Elementary Modal Logics",
journal = j-TOCL,
volume = "17",
number = "1",
pages = "2:1--2:??",
month = dec,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2817825",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We consider the satisfiability problem for modal logic
over first-order definable classes of frames. We
confirm the conjecture from Hemaspaandra and Schnoor
[2008] that modal logic is decidable over classes
definable by universal Horn formulae. We provide a full
classification of Horn formulae with respect to the
complexity of the corresponding satisfiability problem.
It turns out, that except for the trivial case of
inconsistent formulae, local satisfiability is either
NP-complete or PS pace-complete, and global
satisfiability is NP-complete, PSpace-complete, or
ExpTime-complete. We also show that the finite
satisfiability problem for modal logic over Horn
definable classes of frames is decidable. On the
negative side, we show undecidability of two related
problems. First, we exhibit a simple universal
three-variable formula defining the class of frames
over which modal logic is undecidable. Second, we
consider the satisfiability problem of bimodal logic
over Horn definable classes of frames, and also present
a formula leading to undecidability.",
acknowledgement = ack-nhfb,
articleno = "2",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Chretien:2015:SPP,
author = "R{\'e}my Chr{\'e}tien and V{\'e}ronique Cortier and
St{\'e}phanie Delaune",
title = "From Security Protocols to Pushdown Automata",
journal = j-TOCL,
volume = "17",
number = "1",
pages = "3:1--3:??",
month = dec,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2811262",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Formal methods have been very successful in analyzing
security protocols for reachability properties such as
secrecy or authentication. In contrast, there are very
few results for equivalence-based properties, crucial
for studying, for example, privacy-like properties such
as anonymity or vote secrecy. We study the problem of
checking equivalence of security protocols for an
unbounded number of sessions. Since replication leads
very quickly to undecidability (even in the simple case
of secrecy), we focus on a limited fragment of
protocols (standard primitives but pairs, one variable
per protocol's rules) for which the secrecy
preservation problem is known to be decidable.
Surprisingly, this fragment turns out to be undecidable
for equivalence. Then, restricting our attention to
deterministic protocols, we propose the first
decidability result for checking equivalence of
protocols for an unbounded number of sessions. This
result is obtained through a characterization of
equivalence of protocols in terms of equality of
languages of (generalized, real-time) deterministic
pushdown automata. We further show that checking for
equivalence of protocols is actually equivalent to
checking for equivalence of generalized, real-time
deterministic pushdown automata. Very recently, the
algorithm for checking for equivalence of deterministic
pushdown automata has been implemented. We have
implemented our translation from protocols to pushdown
automata, yielding the first tool that decides
equivalence of (some class of) protocols, for an
unbounded number of sessions. As an application, we
have analyzed some protocols of the literature
including a simplified version of the basic access
control (BAC) protocol used in biometric passports.",
acknowledgement = ack-nhfb,
articleno = "3",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Cerrito:2015:OTM,
author = "Serenella Cerrito and Am{\'e}lie David and Valentin
Goranko",
title = "Optimal Tableau Method for Constructive Satisfiability
Testing and Model Synthesis in the Alternating-Time
Temporal Logic {ATL+}",
journal = j-TOCL,
volume = "17",
number = "1",
pages = "4:1--4:??",
month = dec,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2811261",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We develop a sound, complete, and practically
implementable tableau-based decision method for
constructive satisfiability testing and model synthesis
for the fragment ATL$^+$ of the full alternating-time
temporal logic ALT$^*$. The method extends in an
essential way a previously developed tableau-based
decision method for ATL and works in 2EXPTIME, which is
the optimal worst-case complexity of the satisfiability
problem for ATL$^+$. We also discuss how suitable
parameterizations and syntactic restrictions on the
class of input ATL$^+$ formulas can reduce the
complexity of the satisfiability problem.",
acknowledgement = ack-nhfb,
articleno = "4",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Rabe:2015:LTM,
author = "Florian Rabe",
title = "{Lax} Theory Morphisms",
journal = j-TOCL,
volume = "17",
number = "1",
pages = "5:1--5:??",
month = dec,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2818644",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "When relating formal languages, e.g., in logic or type
theory, it is often important to establish
representation theorems. These interpret one language
in terms of another in a way that preserves semantic
properties such as provability or typing. Metalanguages
for stating representation theorems can be divided into
two groups: First, computational languages are very
expressive (usually Turing-complete), but verifying the
representation theorems is very difficult (often
prohibitively so); second, declarative languages are
restricted to certain classes of representation
theorems (often based on theory morphisms), for which
correctness is decidable. Neither is satisfactory, and
this article contributes to the investigation of the
trade-off between these two methods. Concretely, we
introduce lax theory morphisms, which combine some of
the advantages of each: they are substantially more
expressive than conventional theory morphisms, but they
share many of the invariants that make theory morphisms
easy to work with. Specifically, we introduce lax
morphisms between theories of a dependently typed
logical framework, but our approach and results carry
over to most declarative metalanguages. We demonstrate
the usefulness of lax theory morphisms by stating and
verifying a type erasure translation from typed to
untyped first-order logic. The translation is stated as
a single lax theory morphism, and the invariants of the
framework guarantee its correctness. This is the first
time such a complex translation has be verified in a
declarative framework.",
acknowledgement = ack-nhfb,
articleno = "5",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Leino:2015:APS,
author = "K. Rustan M. Leino and Paqui Lucio",
title = "An Assertional Proof of the Stability and Correctness
of {Natural Mergesort}",
journal = j-TOCL,
volume = "17",
number = "1",
pages = "6:1--6:22",
month = dec,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2814571",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/java2010.bib;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present a mechanically verified implementation of
the sorting algorithm Natural Mergesort that consists
of a few methods specified by their contracts of
pre/post conditions. Methods are annotated with
assertions that allow the automatic verification of the
contract satisfaction. This program-proof is made using
the state-of-the-art verifier Dafny. We verify not only
the standard sortedness property, but also that the
algorithm performs a stable sort. Throughout the
article, we provide and explain the complete text of
the program-proof.",
acknowledgement = ack-nhfb,
articleno = "6",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
remark = "From the conclusion on pages 20--21: ``There is no
doubt that sorting algorithms are useful and important
in software. Good algorithms based on ingenious ideas
can be subtle and warrant formal proofs. Indeed, if the
comparison {\tt GT(min,xs.head)} in function {\tt
descending} were replaced by {\tt $ \neg
$GT(xs.head,min)}, then the algorithm would no longer
be stable. An excellent example is the recent
revelation [de Gouw et al. 2015] of the incorrectness
of a very popular sorting algorithm that has been
running since 2002 in billions of computers, cloud
services, and mobile phones. Indeed, it is the default
sorting algorithm for Android SDK, Sun's JDK, and
OpenJDK. The bug was discovered and fixed using the
formal verification tool KeY [Beckert et al. 2007]. The
bug appeared already in the original implementation in
Python.'' The 2015 reference is ``Stijn de Gouw,
Jurriaan Rot, Frank S. de Boer, Richard Bubel, and
Reiner H{\"a}hnle. 2015. \booktitle{OpenJDK's {\tt
java.utils.Collection.sort()} is broken: The good, the
bad and the worst case}. In \booktitle{Computer Aided
Verification. 27th International Conference, CAV 2015}
(LNCS). Springer. doi:10.1007/978-3-319-21690-4_16.''",
}
@Article{Fichte:2015:BND,
author = "Johannes K. Fichte and Stefan Szeider",
title = "Backdoors to Normality for Disjunctive Logic
Programs",
journal = j-TOCL,
volume = "17",
number = "1",
pages = "7:1--7:??",
month = dec,
year = "2015",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2818646",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Sat Jan 9 10:42:43 MST 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The main reasoning problems for disjunctive logic
programs are complete for the second level of the
polynomial hierarchy and hence considered harder than
the same problems for normal (i.e., disjunction-free)
programs, which are on the first level. We propose a
new exact method for solving the disjunctive problems
which exploits the small distance of a disjunctive
programs from being normal. The distance is measured in
terms of the size of a smallest ``backdoor to
normality,'' which is the smallest number of atoms
whose deletion makes the program normal. Our method
consists of three phases. In the first phase, a
smallest backdoor is computed. We show that this can be
done using an efficient algorithm for computing a
smallest vertex cover of a graph. In the second phase,
the backdoor is used to transform the logic program
into a quantified Boolean formula (QBF) where the
number of universally quantified variables equals the
size of the backdoor and where the total size of the
quantified Boolean formula is quasilinear in the size
of the given logic program. The quasilinearity is
achieved by means of a characterization of the least
model of a Horn program in terms of level numberings.
In a third phase, the universal variables are
eliminated using universal expansion yielding a
propositional formula. The blowup in the last phase is
confined to a factor that is exponential in the size of
the backdoor but linear in the size of the quantified
Boolean formula. By checking the satisfiability of the
resulting formula with a S at solver (or by checking
the satisfiability of the quantified Boolean formula by
a Qbf-Sat solver), we can decide the Asp reasoning
problems on the input program. In consequence, we have
a transformation from Asp problems to propositional
satisfiability where the combinatorial explosion, which
is expected when transforming a problem from the second
level of the polynomial hierarchy to the first level,
is confined to a function of the distance to normality
of the input program. In terms of parameterized
complexity, the transformation is fixed-parameter
tractable. We complement this result by showing that
(under plausible complexity-theoretic assumptions) such
a fixed-parameter tractable transformation is not
possible if we consider the distance to tightness
instead of distance to normality.",
acknowledgement = ack-nhfb,
articleno = "7",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Benedikt:2016:EIP,
author = "Michael Benedikt and Balder {Ten Cate} and Michael
{Vanden Boom}",
title = "Effective Interpolation and Preservation in Guarded
Logics",
journal = j-TOCL,
volume = "17",
number = "2",
pages = "8:1--8:??",
month = mar,
year = "2016",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2814570",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 20 09:19:30 MDT 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Desirable properties of a logic include decidability,
and a model theory that inherits properties of
first-order logic, such as interpolation and
preservation theorems. It is known that the Guarded
Fragment (GF) of first-order logic is decidable and
satisfies some preservation properties from first-order
model theory; however, it fails to have Craig
interpolation. The Guarded Negation Fragment (GNF), a
recently defined extension, is known to be decidable
and to have Craig interpolation. Here we give the first
results on effective interpolation for extensions of
GF. We provide an interpolation procedure for GNF whose
complexity matches the doubly exponential upper bound
for satisfiability of GNF. We show that the same
construction gives not only Craig interpolation, but
Lyndon interpolation and relativized interpolation,
which can be used to provide effective proofs of some
preservation theorems. We provide upper bounds on the
size of GNF interpolants for both GNF and GF input, and
complement this with matching lower bounds.",
acknowledgement = ack-nhfb,
articleno = "8",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Liberatore:2016:BME,
author = "Paolo Liberatore",
title = "Belief Merging by Examples",
journal = j-TOCL,
volume = "17",
number = "2",
pages = "9:1--9:??",
month = mar,
year = "2016",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2818645",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 20 09:19:30 MDT 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A common assumption in belief revision is that the
reliability of the information sources is either given,
derived from temporal information, or the same for all.
This article does not describe a new semantics for
integration but studies the problem of obtaining the
reliability of the sources given the result of a
previous merging. As an example, corrections performed
manually on the result of merging some databases may
indicate that the relative reliability of their sources
is different from what was previously assumed, helping
subsequent data mergings.",
acknowledgement = ack-nhfb,
articleno = "9",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bova:2016:MCE,
author = "Simone Bova and Robert Ganian and Stefan Szeider",
title = "Model Checking Existential Logic on Partially Ordered
Sets",
journal = j-TOCL,
volume = "17",
number = "2",
pages = "10:1--10:??",
month = mar,
year = "2016",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2814937",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 20 09:19:30 MDT 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study the problem of checking whether an
existential sentence (i.e., a first-order sentence in
prefix form built using existential quantifiers and all
Boolean connectives) is true in a finite partially
ordered set (a poset). A poset is a reflexive,
antisymmetric, and transitive digraph. The problem
encompasses the fundamental embedding problem of
finding an isomorphic copy of a poset as an induced
substructure of another poset. Model checking
existential logic is already NP-hard on a fixed poset;
thus, we investigate structural properties of posets
yielding conditions for fixed-parameter tractability
when the problem is parameterized by the sentence. We
identify width as a central structural property (the
width of a poset is the maximum size of a subset of
pairwise incomparable elements); our main algorithmic
result is that model checking existential logic on
classes of finite posets of bounded width is
fixed-parameter tractable. We observe a similar
phenomenon in classical complexity, in which we prove
that the isomorphism problem is polynomial-time
tractable on classes of posets of bounded width; this
settles an open problem in order theory. We surround
our main algorithmic result with complexity results on
less restricted, natural neighboring classes of finite
posets, establishing its tightness in this sense. We
also relate our work with (and demonstrate its
independence of) fundamental fixed-parameter
tractability results for model checking on digraphs of
bounded degree and bounded clique-width.",
acknowledgement = ack-nhfb,
articleno = "10",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Albert:2016:MHP,
author = "Elvira Albert and Antonio Flores-Montoya and Samir
Genaim and Enrique Martin-Martin",
title = "May-Happen-in-Parallel Analysis for Actor-Based
Concurrency",
journal = j-TOCL,
volume = "17",
number = "2",
pages = "11:1--11:??",
month = mar,
year = "2016",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2824255",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 20 09:19:30 MDT 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "This article presents a may-happen-in-parallel (MHP)
analysis for languages with actor-based concurrency. In
this concurrency model, actors are the concurrency
units such that, when a method is invoked on an actor
$a_2$ from a task executing on actor $a_1$, statements
of the current task in $a_1$ may run in parallel with
those of the (asynchronous) call on $a_2$, and with
those of transitively invoked methods. The goal of the
MHP analysis is to identify pairs of statements in the
program that may run in parallel in any execution. Our
MHP analysis is formalized as a method-level ( local )
analysis whose information can be modularly composed to
obtain application-level ( global ) information. The
information yielded by the MHP analysis is essential to
infer more complex properties of actor-based concurrent
programs, for example, data race detection, deadlock
freeness, termination, and resource consumption
analyses can greatly benefit from the MHP relations to
increase their accuracy. We report on MayPar, a
prototypical implementation of an MHP static analyzer
for a distributed asynchronous language.",
acknowledgement = ack-nhfb,
articleno = "11",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Demri:2016:ECS,
author = "Stephane Demri and Morgan Deters",
title = "Expressive Completeness of Separation Logic with Two
Variables and No Separating Conjunction",
journal = j-TOCL,
volume = "17",
number = "2",
pages = "12:1--12:??",
month = mar,
year = "2016",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2835490",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 20 09:19:30 MDT 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Separation logic is used as an assertion language for
Hoare-style proof systems about programs with pointers,
and there is an ongoing quest for understanding its
complexity and expressive power. Herein, we show that
first-order separation logic with one record field
restricted to two variables and the separating
implication (no separating conjunction) is as
expressive as weak second-order logic, substantially
sharpening a previous result. Capturing weak
second-order logic with such a restricted form of
separation logic requires substantial updates to known
proof techniques. We develop these and, as a
by-product, identify the smallest fragment of
separation logic known to be undecidable: first-order
separation logic with one record field, two variables,
and no separating conjunction. Because we forbid
ourselves the use of many syntactic resources, this
underscores even further the power of separating
implication on concrete heaps.",
acknowledgement = ack-nhfb,
articleno = "12",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Mamouras:2016:HLD,
author = "Konstantinos Mamouras",
title = "The {Hoare} Logic of Deterministic and
Nondeterministic Monadic Recursion Schemes",
journal = j-TOCL,
volume = "17",
number = "2",
pages = "13:1--13:??",
month = mar,
year = "2016",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2835491",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 20 09:19:30 MDT 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The equational theory of deterministic monadic
recursion schemes is known to be decidable by the
result of S{\'e}nizergues on the decidability of the
problem of DPDA equivalence. In order to capture some
properties of the domain of computation, we augment
equations with certain hypotheses. This preserves the
decidability of the theory, which we call simple
implicational theory. The asymptotically fastest
algorithm known for deciding the equational theory, and
also for deciding the simple implicational theory, has
a running time that is nonelementary. We therefore
consider a restriction of the properties about schemes
to check: instead of arbitrary equations $ f \equiv g $
between schemes, we focus on propositional Hoare
assertions $ \{ p \} f \{ q \} $, where $f$ is a scheme
and $p$, $q$ are tests. Such Hoare assertions have a
straightforward encoding as equations. For this
subclass of program properties, we can also handle
nondeterminism at the syntactic and/or at the semantic
level, without increasing the complexity of the
theories. We investigate the Hoare theory of monadic
recursion schemes, that is, the set of valid
implications whose conclusions are Hoare assertions and
whose premises are of a certain simple form. We present
a sound and complete Hoare-style calculus for this
theory. We also show that the Hoare theory can be
decided in exponential time, and that it is complete
for this class.",
acknowledgement = ack-nhfb,
articleno = "13",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Benedikt:2016:LUO,
author = "Michael Benedikt and Clemens Ley",
title = "Limiting Until in Ordered Tree Query Languages",
journal = j-TOCL,
volume = "17",
number = "2",
pages = "14:1--14:??",
month = mar,
year = "2016",
CODEN = "????",
DOI = "http://dx.doi.org/10.1145/2856104",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Mon Jun 20 09:19:30 MDT 2016",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Marx and de Rijke have shown that the navigational
core of the w3c XML query language XPath is not
first-order complete; that is, it cannot express every
query definable in first-order logic over the
navigational predicates. How can one extend XPath to
get a first-order complete language? Marx has shown
that Conditional XPath-an extension of XPath with an
``Until'' operator-is first-order complete. The
completeness argument makes essential use of the
presence of upward axes in Conditional XPath. We
examine whether it is possible to get ``forward-only''
languages that are first-order complete for Boolean
queries on ordered trees. It is easy to see that a
variant of the temporal logic CTL$^*$ is first-order
complete; the variant has path quantifiers for
downward, leftward, and rightward paths, while along a
path one can check arbitrary formulas of Linear
Temporal Logic (LTL). This language has two major
disadvantages: It requires path quantification in both
horizontal directions (in particular, it requires
looking backward at the prior siblings of a node), and
it requires the consideration of formulas of LTL of
arbitrary complexity on vertical paths. This last is in
contrast with Marx's Conditional XPath, which requires
only the checking of a single Until operator on a path.
We investigate whether either of these restrictions can
be eliminated. Our main results are negative ones. We
show that if we restrict our CTL$^*$ language by having
an Until operator in only one horizontal direction,
then we lose completeness. We also show that no
restriction to a ``small'' subset of LTL along vertical
paths is sufficient for first-order completeness.
Smallness here means of bounded ``Until Depth,'' a
measure of complexity of LTL formulas defined by
Etessami and Wilke. In particular, it follows from our
work that Conditional XPath with only forward axes is
not expressively complete; this extends results proved
by Rabinovich and Maoz in the context of infinite
unordered trees.",
acknowledgement = ack-nhfb,
articleno = "14",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Dongol:2016:CUC,
author = "Brijesh Dongol and Ian J. Hayes and Georg Struth",
title = "Convolution as a Unifying Concept: Applications in
Separation Logic, Interval Calculi, and Concurrency",
journal = j-TOCL,
volume = "17",
number = "3",
pages = "15:1--15:??",
month = jul,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2874773",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:13 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "A notion of convolution is presented in the context of
formal power series together with lifting constructions
characterising algebras of such series, which usually
are quantales. A number of examples underpin the
universality of these constructions, the most prominent
ones being separation logics, where convolution is
separating conjunction in an assertion quantale;
interval logics, where convolution is the chop
operation; and stream interval functions, where
convolution is proposed for analysing the trajectories
of dynamical or real-time systems. A Hoare logic can be
constructed in a generic fashion on the power-series
quantale, which applies to each of these examples. In
many cases, commutative notions of convolution have
natural interpretations as concurrency operations.",
acknowledgement = ack-nhfb,
articleno = "15",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Lazic:2016:ZHH,
author = "Ranko Lazi{\'c} and Jo{\"e}l Ouaknine and James
Worrell",
title = "{Zeno}, {Hercules}, and the {Hydra}: Safety Metric
Temporal Logic is {Ackermann}-Complete",
journal = j-TOCL,
volume = "17",
number = "3",
pages = "16:1--16:??",
month = jul,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2874774",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:13 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Metric temporal logic (MTL) is one of the most
prominent specification formalisms for real-time
systems. Over infinite timed words, full MTL is
undecidable, but satisfiability for a syntactially
defined safety fragment, called safety MTL, was proved
decidable several years ago. Satisfiability for safety
MTL is also known to be equivalent to a fair
termination problem for a class of channel machines
with insertion errors. However, hitherto, its precise
computational complexity has remained elusive, with
only a nonelementary lower bound. Via another
equivalent problem, namely termination for a class of
rational relations, we show that satisfiability for
safety MTL is Ackermann-complete (i.e., among the
easiest nonprimitive recursive problems). This is
surprising since decidability was originally
established using Higman's Lemma, suggesting a much
higher nonmultiply recursive complexity.",
acknowledgement = ack-nhfb,
articleno = "16",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Ciabattoni:2016:PLS,
author = "Agata Ciabattoni and Revantha Ramanayake",
title = "Power and Limits of Structural Display Rules",
journal = j-TOCL,
volume = "17",
number = "3",
pages = "17:1--17:??",
month = jul,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2874775",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:13 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "What can (and cannot) be expressed by structural
display rules? Given a display calculus, we present a
systematic procedure for transforming axioms into
structural rules. The conditions for the procedure are
given in terms of (purely syntactic) abstract
properties of the base calculus; thus, the method
applies to large classes of calculi and logics. If the
calculus satisfies certain additional properties, we
prove the converse direction, thus characterising the
class of axioms that can be captured by structural
display rules. Determining if an axiom belongs to this
class or not is shown to be decidable. Applied to the
display calculus for tense logic, we obtain a new proof
of Kracht's Display Theorem I.",
acknowledgement = ack-nhfb,
articleno = "17",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Drabent:2016:CCL,
author = "Wlodzimierz Drabent",
title = "Correctness and Completeness of Logic Programs",
journal = j-TOCL,
volume = "17",
number = "3",
pages = "18:1--18:??",
month = jul,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2898434",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:13 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We discuss proving correctness and completeness of
definite clause logic programs. We propose a method for
proving completeness, while for proving correctness we
employ a method that should be well known but is often
neglected. Also, we show how to prove completeness and
correctness in the presence of SLD-tree pruning, and
point out that approximate specifications simplify
specifications and proofs. We compare the proof methods
to declarative diagnosis (algorithmic debugging),
showing that approximate specifications eliminate a
major drawback of the latter. We argue that our proof
methods reflect natural declarative thinking about
programs, and that they can be used, formally or
informally, in everyday programming.",
acknowledgement = ack-nhfb,
articleno = "18",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Atserias:2016:NPM,
author = "Albert Atserias and Massimo Lauria and Jakob
Nordstr{\"o}m",
title = "Narrow Proofs May Be Maximally Long",
journal = j-TOCL,
volume = "17",
number = "3",
pages = "19:1--19:??",
month = jul,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2898435",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:13 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We prove that there are 3-CNF formulas over n
variables that can be refuted in resolution in width
$w$ but require resolution proofs of size $ n^{\Omega
(w)}$. This shows that the simple counting argument
that any formula refutable in width w must have a proof
in size $ n^{O(w)}$ is essentially tight. Moreover, our
lower bound generalizes to polynomial calculus
resolution and Sherali--Adams, implying that the
corresponding size upper bounds in terms of degree and
rank are tight as well. The lower bound does not extend
all the way to Lasserre, however, since we show that
there the formulas we study have proofs of constant
rank and size polynomial in both $n$ and $w$.",
acknowledgement = ack-nhfb,
articleno = "19",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Creignou:2016:BMW,
author = "Nadia Creignou and Odile Papini and Stefan R{\"u}mmele
and Stefan Woltran",
title = "Belief Merging within Fragments of Propositional
Logic",
journal = j-TOCL,
volume = "17",
number = "3",
pages = "20:1--20:??",
month = jul,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2898436",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:13 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Recently, belief change within the framework of
fragments of propositional logic has gained increasing
attention. Previous research focused on belief
contraction and belief revision on the Horn fragment.
However, the problem of belief merging within fragments
of propositional logic has been mostly neglected so
far. We present a general approach to defining new
merging operators derived from existing ones such that
the result of merging remains in the fragment under
consideration. Our approach is not limited to the case
of Horn fragment; it is applicable to any fragment of
propositional logic characterized by a closure property
on the sets of models of its formul{\ae}. We study the
logical properties of the proposed operators regarding
satisfaction of merging postulates, considering, in
particular, distance-based merging operators for Horn
and Krom fragments.",
acknowledgement = ack-nhfb,
articleno = "20",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Trybus:2016:RRB,
author = "Adam Trybus",
title = "Rational Region-Based Affine Logic of the Real Plane",
journal = j-TOCL,
volume = "17",
number = "3",
pages = "21:1--21:??",
month = jul,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2897190",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:13 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The region-based spatial logics, where variables are
set to range over certain subsets of geometric space,
are the focal point of the qualitative spatial
reasoning, a subfield of the KR\&R research area. A lot
of attention has been devoted to developing the
topological spatial logics, leaving other systems
relatively underexplored. We are concerned with a
specific example of a region-based affine spatial
logic. Building on the previous results on spatial
logics with convexity, we axiomatise the theory of $ M
= \langle R O Q(R^2), {\rm conv}^M, \leq^M \rangle $,
where $ R O Q(R^2) $ is the set of regular open
rational polygons of the real plane; $ {\rm conv}^M $
is the convexity property and $ l e q^M $ is the
inclusion relation. The axiomatisation uses two
infinitary rules of inference and a number of axiom
schemas.",
acknowledgement = ack-nhfb,
articleno = "21",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Wen:2016:MPT,
author = "Lian Wen and Kewen Wang and Yi-Dong Shen and Fangzhen
Lin",
title = "A Model for Phase Transition of Random Answer-Set
Programs",
journal = j-TOCL,
volume = "17",
number = "3",
pages = "22:1--22:??",
month = jul,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2926791",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:13 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "The critical behaviors of NP-complete problems have
been studied extensively, and numerous results have
been obtained for Boolean formula satisfiability (SAT)
and constraint satisfaction (CSP), among others.
However, few results are known for the critical
behaviors of NP-hard nonmonotonic reasoning problems so
far; in particular, a mathematical model for phase
transition in nonmonotonic reasoning is still missing.
In this article, we investigate the phase transition of
negative two-literal logic programs under the
answer-set semantics. We choose this class of logic
programs since it is the simplest class for which the
consistency problem of deciding if a program has an
answer set is still NP-complete. We first introduce a
new model, called quadratic model for generating random
logic programs in this class. We then mathematically
prove that the consistency problem for this class of
logic programs exhibits a phase transition.
Furthermore, the phase-transition follows an
easy-hard-easy pattern. Given the correspondence
between answer sets for negative two-literal programs
and kernels for graphs, as a corollary, our result
significantly generalizes de la Vega's well-known
theorem for phase transition on the existence of
kernels in random graphs. We also report some
experimental results. Given our mathematical results,
these experimental results are not really necessary. We
include them here as they suggest that our
phase-transition result is more general and likely
holds for more general classes of logic programs.",
acknowledgement = ack-nhfb,
articleno = "22",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Chadha:2016:AVE,
author = "Rohit Chadha and Vincent Cheval and Stefan Ciob{\^a}ca
and Steve Kremer",
title = "Automated Verification of Equivalence Properties of
Cryptographic Protocols",
journal = j-TOCL,
volume = "17",
number = "4",
pages = "23:1--23:??",
month = nov,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2926715",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:14 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/cryptography2010.bib;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Indistinguishability properties are essential in
formal verification of cryptographic protocols. They
are needed to model anonymity properties, strong
versions of confidentiality, and resistance against
offline guessing attacks. Indistinguishability
properties can be conveniently modeled as equivalence
properties. We present a novel procedure to verify
equivalence properties for a bounded number of sessions
of cryptographic protocols. As in the applied pi
calculus, our protocol specification language is
parametrized by a first-order sorted term signature and
an equational theory that allows formalization of
algebraic properties of cryptographic primitives. Our
procedure is able to verify trace equivalence for
determinate cryptographic protocols. On determinate
protocols, trace equivalence coincides with
observational equivalence, which can therefore be
automatically verified for such processes. When
protocols are not determinate, our procedure can be
used for both under- and over-approximations of trace
equivalence, which proved successful on examples. The
procedure can handle a large set of cryptographic
primitives, namely those whose equational theory is
generated by an optimally reducing convergent rewrite
system. The procedure is based on a fully abstract
modelling of the traces of a bounded number of sessions
of the protocols into first-order Horn clauses on which
a dedicated resolution procedure is used to decide
equivalence properties. We have shown that our
procedure terminates for the class of subterm
convergent equational theories. Moreover, the procedure
has been implemented in a prototype tool Active
Knowledge in Security Protocols and has been
effectively tested on examples. Some of the examples
were outside the scope of existing tools, including
checking anonymity of an electronic voting protocol due
to Okamoto.",
acknowledgement = ack-nhfb,
articleno = "23",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Facchini:2016:IPG,
author = "Alessandro Facchini and Filip Murlak and Michal
Skrzypczak",
title = "Index Problems for Game Automata",
journal = j-TOCL,
volume = "17",
number = "4",
pages = "24:1--24:??",
month = nov,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2946800",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:14 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "For a given regular language of infinite trees, one
can ask about the minimal number of priorities needed
to recognize this language with a nondeterministic,
alternating, or weak alternating parity automaton.
These questions are known as, respectively, the
nondeterministic, alternating, and weak Rabin-Mostowski
index problems. Whether they can be answered
effectively is a long-standing open problem, solved so
far only for languages recognizable by deterministic
automata (the alternating variant trivializes). We
investigate a wider class of regular languages,
recognizable by so-called game automata, which can be
seen as the closure of deterministic ones under
complementation and composition. Game automata are
known to recognize languages arbitrarily high in the
alternating Rabin-Mostowski index hierarchy; that is,
the alternating index problem does not trivialize
anymore. Our main contribution is that all three index
problems are decidable for languages recognizable by
game automata. Additionally, we show that it is
decidable whether a given regular language can be
recognized by a game automaton.",
acknowledgement = ack-nhfb,
articleno = "24",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Elberfeld:2016:WFO,
author = "Michael Elberfeld and Martin Grohe and Till Tantau",
title = "Where First-Order and Monadic Second-Order Logic
Coincide",
journal = j-TOCL,
volume = "17",
number = "4",
pages = "25:1--25:??",
month = nov,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2946799",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:14 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study on which classes of graphs first-order logic
( fo) and monadic second-order logic (mso) have the
same expressive power. We show that for all classes C
of graphs that are closed under taking subgraphs, fo
and mso have the same expressive power on C if and only
if, C has bounded tree depth. Tree depth is a graph
invariant that measures the similarity of a graph to a
star in a similar way that tree width measures the
similarity of a graph to a tree. For classes just
closed under taking induced subgraphs, we show an
analogous result for guarded second-order logic (gso),
the variant of mso that not only allows quantification
over vertex sets but also over edge sets. A key tool in
our proof is a Feferman--Vaught-type theorem that works
for infinite collections of structures despite being
constructive.",
acknowledgement = ack-nhfb,
articleno = "25",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Carlucci:2016:PCP,
author = "Lorenzo Carlucci and Nicola Galesi and Massimo
Lauria",
title = "On the Proof Complexity of {Paris--Harrington} and
Off-Diagonal {Ramsey} Tautologies",
journal = j-TOCL,
volume = "17",
number = "4",
pages = "26:1--26:??",
month = nov,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2946801",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:14 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study the proof complexity of Paris-Harrington's
Large Ramsey Theorem for bi-colorings of graphs and of
off-diagonal Ramsey's Theorem. For Paris-Harrington, we
prove a non-trivial conditional lower bound in
Resolution and a non-trivial upper bound in
bounded-depth Frege. The lower bound is conditional on
a (very reasonable) hardness assumption for a weak
(quasi-polynomial) Pigeonhole principle in R es(2). We
show that under such an assumption, there is no
refutation of the Paris-Harrington formulas of size
quasi-polynomial in the number of propositional
variables. The proof technique for the lower bound
extends the idea of using a combinatorial principle to
blow up a counterexample for another combinatorial
principle beyond the threshold of inconsistency. A
strong link with the proof complexity of an unbalanced
off-diagonal Ramsey principle is established. This is
obtained by adapting some constructions due to
Erd{\H{o}}s and Mills. We prove a non-trivial
Resolution lower bound for a family of such
off-diagonal Ramsey principles.",
acknowledgement = ack-nhfb,
articleno = "26",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Bogaerts:2016:WFS,
author = "Bart Bogaerts and Joost Vennekens and Marc Denecker",
title = "On Well-Founded Set-Inductions and Locally Monotone
Operators",
journal = j-TOCL,
volume = "17",
number = "4",
pages = "27:1--27:??",
month = nov,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2963096",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:14 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In the past, compelling arguments in favour of the
well-founded semantics for autoepistemic logic have
been presented. In this article, we show that for
certain classes of theories, this semantics fails to
identify the unique intended model. We solve this
problem by refining the well-founded semantics. We
develop our work in approximation fixpoint theory, an
abstract algebraical study of semantics of nonmonotonic
logics. As such, our results also apply to logic
programming, default logic, Dung's argumentation
frameworks, and abstract dialectical frameworks.",
acknowledgement = ack-nhfb,
articleno = "27",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Furusawa:2016:TM,
author = "Hitoshi Furusawa and Georg Struth",
title = "Taming Multirelations",
journal = j-TOCL,
volume = "17",
number = "4",
pages = "28:1--28:??",
month = nov,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2964907",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:14 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Binary multirelations generalise binary relations by
associating elements of a set to its subsets. We study
the structure and algebra of multirelations under the
operations of union, intersection, sequential, and
parallel composition, as well as finite and infinite
iteration. Starting from a set-theoretic investigation,
we propose axiom systems for multirelations in contexts
ranging from bi-monoids to bi-quantales.",
acknowledgement = ack-nhfb,
articleno = "28",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Sojakova:2016:ETP,
author = "Kristina Sojakova",
title = "The Equivalence of the Torus and the Product of Two
Circles in Homotopy Type Theory",
journal = j-TOCL,
volume = "17",
number = "4",
pages = "29:1--29:??",
month = nov,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2992783",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:14 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Homotopy type theory is a new branch of mathematics
that merges insights from abstract homotopy theory and
higher category theory with those of logic and type
theory. It allows us to represent a variety of
mathematical objects as basic type-theoretic
construction, higher inductive types. We present a
proof that in homotopy type theory, the torus is
equivalent to the product of two circles. This result
indicates that the synthetic definition of torus as a
higher inductive type is indeed correct.",
acknowledgement = ack-nhfb,
articleno = "29",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Schubert:2016:HHP,
author = "Aleksy Schubert and Pawel Urzyczyn and Daria
Walukiewicz-Chrzaszcz",
title = "How Hard Is Positive Quantification?",
journal = j-TOCL,
volume = "17",
number = "4",
pages = "30:1--30:??",
month = nov,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2981544",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:14 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We show that the constructive predicate logic with
positive (covariant) quantification is hard for doubly
exponential universal time, that is, for the class co-
2-N exptime. Our approach is to represent proof-search
as computation of an alternating automaton. The memory
of the automaton is structured in a way that strictly
corresponds to scopes of the binders used in the
constructed proof. This provides an application of
automata-theoretic techniques in proof theory.",
acknowledgement = ack-nhfb,
articleno = "30",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Charatonik:2016:TVL,
author = "Witold Charatonik and Piotr Witkowski",
title = "Two-Variable Logic with Counting and Trees",
journal = j-TOCL,
volume = "17",
number = "4",
pages = "31:1--31:??",
month = nov,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2983622",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:14 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We consider the two-variable logic with counting
quantifiers (C$^2$ ) interpreted over finite structures
that contain two forests of ranked trees. This logic is
strictly more expressive than standard C$^2$ and it is
no longer a fragment of first-order logic. In
particular, it can express that a structure is a ranked
tree, a cycle, or a connected graph of bounded degree.
It is also strictly more expressive than first-order
logic with two variables and two successor relations of
two finite linear orders. We present a decision
procedure for the satisfiability problem for this
logic. The procedure runs in NE xpTime, which is
optimal since the satisfiability problem for plain
C$^2$ is NExpTime-complete.",
acknowledgement = ack-nhfb,
articleno = "31",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Benaim:2016:CTV,
author = "Saguy Benaim and Michael Benedikt and Witold
Charatonik and Emanuel Kiero'nski and Rastislav
Lenhardt and Filip Mazowiecki and James Worrell",
title = "Complexity of Two-Variable Logic on Finite Trees",
journal = j-TOCL,
volume = "17",
number = "4",
pages = "32:1--32:??",
month = nov,
year = "2016",
CODEN = "????",
DOI = "https://doi.org/10.1145/2996796",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Wed Mar 15 16:49:14 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Verification of properties expressed in the
two-variable fragment of first-order logic FO$^2$ has
been investigated in a number of contexts. The
satisfiability problem for FO$^2$ over arbitrary
structures is known to be NEXPTIME-complete, with
satisfiable formulas having exponential-sized models.
Over words, where FO$^2$ is known to have the same
expressiveness as unary temporal logic, satisfiability
is again NEXPTIME-complete. Over finite labelled
ordered trees, FO$^2$ has the same expressiveness as
navigational XPath, a popular query language for XML
documents. Prior work on XPath and FO$^2$ gives a
2EXPTIME bound for satisfiability of FO$^2$ over trees.
This work contains a comprehensive analysis of the
complexity of FO$^2$ on trees, and on the size and
depth of models. We show that different techniques are
required depending on the vocabulary used, whether the
trees are ranked or unranked, and the encoding of
labels on trees. We also look at a natural restriction
of FO$^2$, its guarded version, GF$^2$. Our results
depend on an analysis of types in models of FO$^2$
formulas, including techniques for controlling the
number of distinct subtrees, the depth, and the size of
a witness to satisfiability for FO$^2$ sentences over
finite trees.",
acknowledgement = ack-nhfb,
articleno = "32",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Luck:2017:PCS,
author = "Martin L{\"u}ck and Arne Meier and Irena Schindler",
title = "Parametrised Complexity of Satisfiability in Temporal
Logic",
journal = j-TOCL,
volume = "18",
number = "1",
pages = "1:1--1:??",
month = apr,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3001835",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 13 17:53:54 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We apply the concept of formula treewidth and
pathwidth to computation tree logic, linear temporal
logic, and the full branching time logic. Several
representations of formulas as graphlike structures are
discussed, and corresponding notions of treewidth and
pathwidth are introduced. As an application for such
structures, we present a classification in terms of
parametrised complexity of the satisfiability problem,
where we make use of Courcelle's famous theorem for
recognition of certain classes of structures. Our
classification shows a dichotomy between W[1]-hard and
fixed-parameter tractable operator fragments almost
independently of the chosen graph representation. The
only fragments that are proven to be fixed-parameter
tractable (FPT) are those that are restricted to the X
operator. By investigating Boolean operator fragments
in the sense of Post's lattice, we achieve the same
complexity as in the unrestricted case if the set of
available Boolean functions can express the function
``negation of the implication.'' Conversely, we show
containment in FPT for almost all other clones.",
acknowledgement = ack-nhfb,
articleno = "1",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Dapic:2017:QCS,
author = "Petar Dapi{\'c} and Petar Markovi{\'c} and Barnaby
Martin",
title = "Quantified Constraint Satisfaction Problem on
Semicomplete Digraphs",
journal = j-TOCL,
volume = "18",
number = "1",
pages = "2:1--2:??",
month = apr,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3007899",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 13 17:53:54 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study the (non-uniform) quantified constraint
satisfaction problem QCSP( H ) as H ranges over
semicomplete digraphs. We obtain a complexity-theoretic
trichotomy: QCSP( H ) is either in P, is NP-complete,
or is Pspace-complete. The largest part of our work is
the algebraic classification of precisely which
semicomplete digraphs enjoy only essentially unary
polymorphisms, which is combinatorially interesting in
its own right.",
acknowledgement = ack-nhfb,
articleno = "2",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Kojima:2017:HLG,
author = "Kensuke Kojima and Atsushi Igarashi",
title = "A {Hoare} Logic for {GPU} Kernels",
journal = j-TOCL,
volume = "18",
number = "1",
pages = "3:1--3:??",
month = apr,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3001834",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 13 17:53:54 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/multithreading.bib;
http://www.math.utah.edu/pub/tex/bib/pvm.bib;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study a Hoare Logic to reason about parallel
programs executed on graphics processing units (GPUs),
called GPU kernels. During the execution of GPU
kernels, multiple threads execute in lockstep, that is,
execute the same instruction simultaneously. When the
control branches, the two branches are executed
sequentially, but during the execution of each branch
only those threads that take it are enabled; after the
control converges, all the threads are enabled and
again execute in lockstep. In this article, we first
consider a semantics in which all threads execute in
lockstep (this semantics simplifies the actual
execution model of GPUs) and adapt Hoare Logic to this
setting by augmenting the usual Hoare triples with an
additional component representing the set of enabled
threads. It is determined that the soundness and
relative completeness of the logic do not hold for all
programs; a difficulty arises from the fact that one
thread can invalidate the loop termination condition of
another thread through shared memory. We overcome this
difficulty by identifying an appropriate class of
programs for which the soundness and relative
completeness hold. Additionally, we discuss thread
interleaving, which is present in the actual execution
of GPUs but not in the lockstep semantics mentioned
above. We show that if a program is race free, then the
lockstep and interleaving semantics produce the same
result. This implies that our logic is sound and
relatively complete for race-free programs, even if the
thread interleaving is taken into account.",
acknowledgement = ack-nhfb,
articleno = "3",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Sangiorgi:2017:ECU,
author = "Davide Sangiorgi",
title = "Equations, Contractions, and Unique Solutions",
journal = j-TOCL,
volume = "18",
number = "1",
pages = "4:1--4:??",
month = apr,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/2971339",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 13 17:53:54 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "One of the most studied behavioural equivalences is
bisimilarity. Its success is much due to the associated
bisimulation proof method, which can be further
enhanced by means of ``bisimulation up-to'' techniques
such as ``up-to context.'' A different proof method is
discussed, based on a unique solution of special forms
of inequations called contractions and inspired by
Milner's theorem on unique solution of equations. The
method is as powerful as the bisimulation proof method
and its ``up-to context'' enhancements. The definition
of contraction can be transferred onto other
behavioural equivalences, possibly contextual and
non-coinductive. This enables a coinductive reasoning
style on such equivalences, either by applying the
method based on unique solution of contractions or by
injecting appropriate contraction preorders into the
bisimulation game. The techniques are illustrated in
CCS-like languages; an example dealing with
higher-order languages is also shown.",
acknowledgement = ack-nhfb,
articleno = "4",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Ameloot:2017:DQD,
author = "Tom J. Ameloot and Bas Ketsman and Frank Neven and
Daniel Zinn",
title = "{Datalog} Queries Distributing over Components",
journal = j-TOCL,
volume = "18",
number = "1",
pages = "5:1--5:??",
month = apr,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3022743",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 13 17:53:54 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We investigate the class D of queries that distribute
over components. These are the queries that can be
evaluated by taking the union of the query results over
the connected components of the database instance. We
show that it is undecidable whether a (positive)
Datalog program distributes over components.
Additionally, we show that connected Datalog\isonot
(the fragment of Datalog\isonot where all rules are
connected) provides an effective syntax for
Datalog\isonot programs that distribute over components
under the stratified as well as under the well-founded
semantics. As a corollary, we obtain a simple proof for
one of the main results in previous work [Zinn et al.
2012], namely that the classic win-move query is in
F$_2$ (a particular class of coordination-free
queries).",
acknowledgement = ack-nhfb,
articleno = "5",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Haret:2017:MHF,
author = "Adrian Haret and Stefan R{\"u}mmele and Stefan
Woltran",
title = "Merging in the {Horn} Fragment",
journal = j-TOCL,
volume = "18",
number = "1",
pages = "6:1--6:??",
month = apr,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3043700",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 13 17:53:54 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Belief merging is a central operation within the field
of belief change and addresses the problem of combining
multiple, possibly mutually inconsistent knowledge
bases into a single, consistent one. A current research
trend in belief change is concerned with representation
theorems tailored to fragments of logic, in particular
Horn logic. Hereby, the goal is to guarantee that the
result of the change operations stays within the
fragment under consideration. While several such
results have been obtained for Horn revision and Horn
contraction, merging of Horn theories has been
neglected so far. In this article, we provide a novel
representation theorem for Horn merging by
strengthening the standard merging postulates.
Moreover, we present concrete Horn merging operators
satisfying all postulates.",
acknowledgement = ack-nhfb,
articleno = "6",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Mastroeni:2017:APS,
author = "Isabella Mastroeni and Damiano Zanardini",
title = "Abstract Program Slicing: an Abstract
Interpretation-Based Approach to Program Slicing",
journal = j-TOCL,
volume = "18",
number = "1",
pages = "7:1--7:??",
month = apr,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3029052",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Thu Apr 13 17:53:54 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In the present article, we formally define the notion
of abstract program slicing, a general form of program
slicing where properties of data are considered instead
of their exact value. This approach is applied to a
language with numeric and reference values and relies
on the notion of abstract dependencies between program
statements. The different forms of (backward) abstract
slicing are added to an existing formal framework where
traditional, nonabstract forms of slicing could be
compared. The extended framework allows us to
appreciate that abstract slicing is a generalization of
traditional slicing, since each form of traditional
slicing (dealing with syntactic dependencies) is
generalized by a semantic (nonabstract) form of
slicing, which is actually equivalent to an abstract
form where the identity abstraction is performed on
data. Sound algorithms for computing abstract
dependencies and a systematic characterization of
program slices are provided, which rely on the notion
of agreement between program states.",
acknowledgement = ack-nhfb,
articleno = "7",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Chlebowski:2017:AGE,
author = "Szymon Chlebowski and Maciej Komosinski and Adam
Kups",
title = "Automated Generation of Erotetic Search Scenarios:
Classification, Optimization, and Knowledge
Extraction",
journal = j-TOCL,
volume = "18",
number = "2",
pages = "8:1--8:??",
month = jun,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3056537",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Jun 23 17:25:24 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "This article concerns automated generation and
processing of erotetic search scenarios (ESSs). ESSs
are formal constructs characterized in Inferential
Erotetic Logic that enable finding possible answers to
a posed question by decomposing it into auxiliary
questions. The first part of this work describes a
formal account on ESSs. The formal approach is then
applied to automatically generate ESSs, and the
resulting scenarios are evaluated according to a number
of criteria. These criteria are subjected to
discordance analysis that reveals their mutual
relationships. Finally, knowledge concerning
relationships between different values of evaluation
criteria is extracted by applying Apriori-an
association rules mining algorithm. The proposed
approach of integration of formal erotetic logic with
computational tools provides extensive insight into the
former and helps with the development of efficient
ESSs.",
acknowledgement = ack-nhfb,
articleno = "8",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Zhang:2017:ELP,
author = "Heng Zhang and Yan Zhang",
title = "Expressiveness of Logic Programs under the General
Stable Model Semantics",
journal = j-TOCL,
volume = "18",
number = "2",
pages = "9:1--9:??",
month = jun,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3039244",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Jun 23 17:25:24 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Stable model semantics had been recently generalized
to non-Herbrand structures by several works, which
provides a unified framework and solid logical
foundations for answer set programming. This article
focuses on the expressiveness of normal and disjunctive
logic programs under general stable model semantics. A
translation from disjunctive logic programs to normal
logic programs is proposed for infinite structures.
Over finite structures, some disjunctive logic programs
are proved to be intranslatable to normal logic
programs if the arities of auxiliary predicates and
functions are bounded in a certain way. The equivalence
of the expressiveness of normal logic programs and
disjunctive logic programs over arbitrary structures is
also shown to coincide with that over finite structures
and coincide with whether the complexity class NP is
closed under complement. Moreover, to obtain a more
explicit picture of the expressiveness, some
intertranslatability results between logic program
classes, and fragments of second-order logic are
established.",
acknowledgement = ack-nhfb,
articleno = "9",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Barcelo:2017:GLR,
author = "Pablo Barcel{\'o} and Pablo Mu{\~n}oz",
title = "Graph Logics with Rational Relations: The Role of Word
Combinatorics",
journal = j-TOCL,
volume = "18",
number = "2",
pages = "10:1--10:??",
month = jun,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3070822",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Jun 23 17:25:24 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Graph databases make use of logics that combine
traditional first-order features with navigation on
paths, in the same way logics for model checking do.
However, modern applications of graph databases impose
a new requirement on the expressiveness of the logics:
they need comparing labels of paths based on word
relations (such as prefix, subword, or subsequence).
This has led to the study of logics that extend basic
graph languages with features for comparing labels of
paths based on regular relations or the strictly more
powerful rational relations. The evaluation problem for
the former logic is decidable (and even tractable in
data complexity), but already extending this logic with
such a common rational relation as subword or suffix
makes evaluation undecidable. In practice, however, it
is rare to have the need for such powerful logics.
Therefore, it is more realistic to study the complexity
of less expressive logics that still allow comparing
paths based on practically motivated rational
relations. Here we concentrate on the most basic
languages, which extend graph pattern logics with path
comparisons based only on suffix, subword, or
subsequence. We pinpoint the complexity of evaluation
for each one of these logics, which shows that all of
them are decidable in elementary time (P space or
NExptime). Furthermore, the extension with suffix is
even tractable in data complexity (but the other two
are not). In order to obtain our results we establish a
link between the evaluation problem for graph logics
and two important problems in word combinatorics: word
equations with regular constraints and longest common
subsequence.",
acknowledgement = ack-nhfb,
articleno = "10",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Beckmann:2017:NSP,
author = "Arnold Beckmann and Sam Buss",
title = "The {NP} Search Problems of {Frege} and Extended
{Frege} Proofs",
journal = j-TOCL,
volume = "18",
number = "2",
pages = "11:1--11:??",
month = jun,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3060145",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Jun 23 17:25:24 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We study consistency search problems for Frege and
extended Frege proofs-namely the NP search problems of
finding syntactic errors in Frege and extended Frege
proofs of contradictions. The input is a polynomial
time function, or an oracle, describing a proof of a
contradiction; the output is the location of a
syntactic error in the proof. The consistency search
problems for Frege and extended Frege systems are shown
to be many-one complete for the provably total NP
search problems of the second-order bounded arithmetic
theories U$^1_2$ and V$^1_2$, respectively.",
acknowledgement = ack-nhfb,
articleno = "11",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Daca:2017:FSM,
author = "Przemyslaw Daca and Thomas A. Henzinger and Jan
Kret{\'\i}nsk{\'y} and Tatjana Petrov",
title = "Faster Statistical Model Checking for Unbounded
Temporal Properties",
journal = j-TOCL,
volume = "18",
number = "2",
pages = "12:1--12:??",
month = jun,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3060139",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Jun 23 17:25:24 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We present a new algorithm for the statistical model
checking of Markov chains with respect to unbounded
temporal properties, including full linear temporal
logic. The main idea is that we monitor each simulation
run on the fly, in order to detect quickly if a bottom
strongly connected component is entered with high
probability, in which case the simulation run can be
terminated early. As a result, our simulation runs are
often much shorter than required by termination bounds
that are computed a priori for a desired level of
confidence on a large state space. In comparison to
previous algorithms for statistical model checking our
method is not only faster in many cases but also
requires less information about the system, namely,
only the minimum transition probability that occurs in
the Markov chain. In addition, our method can be
generalised to unbounded quantitative properties such
as mean-payoff bounds.",
acknowledgement = ack-nhfb,
articleno = "12",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Groote:2017:ACS,
author = "Jan Friso Groote and David N. Jansen and Jeroen J. A.
Keiren and Anton J. Wijs",
title = "An {$ O(m \log n) $} Algorithm for Computing
Stuttering Equivalence and Branching Bisimulation",
journal = j-TOCL,
volume = "18",
number = "2",
pages = "13:1--13:??",
month = jun,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3060140",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Jun 23 17:25:24 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "We provide a new algorithm to determine stuttering
equivalence with time complexity $ O(m \log n) $, where
$n$ is the number of states and $m$ is the number of
transitions of a Kripke structure. This algorithm can
also be used to determine branching bisimulation in $
O(m (\log | A c t | + \log n))$ time, where Act is the
set of actions in a labeled transition system.
Theoretically, our algorithm substantially improves
upon existing algorithms, which all have time
complexity of the form $ O(m n)$ at best. Moreover, it
has better or equal space complexity. Practical results
confirm these findings: they show that our algorithm
can outperform existing algorithms by several orders of
magnitude, especially when the Kripke structures are
large. The importance of our algorithm stretches far
beyond stuttering equivalence and branching
bisimulation. The known $ O(m n)$ algorithms were
already far more efficient (both in space and time)
than most other algorithms to determine behavioral
equivalences (including weak bisimulation), and
therefore they were often used as an essential
preprocessing step. This new algorithm makes this use
of stuttering equivalence and branching bisimulation
even more attractive.",
acknowledgement = ack-nhfb,
articleno = "13",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Fuhs:2017:VPP,
author = "Carsten Fuhs and Cynthia Kop and Naoki Nishida",
title = "Verifying Procedural Programs via Constrained
Rewriting Induction",
journal = j-TOCL,
volume = "18",
number = "2",
pages = "14:1--14:??",
month = jun,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3060143",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Jun 23 17:25:24 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "This article aims to develop a verification method for
procedural programs via a transformation into logically
constrained term rewriting systems (LCTRSs). To this
end, we extend transformation methods based on integer
term rewriting systems to handle arbitrary data types,
global variables, function calls, and arrays, and to
encode safety checks. Then we adapt existing rewriting
induction methods to LCTRSs and propose a simple yet
effective method to generalize equations. We show that
we can automatically verify memory safety and prove
correctness of realistic functions. Our approach proves
equivalence between two implementations; thus, in
contrast to other works, we do not require an explicit
specification in a separate specification language.",
acknowledgement = ack-nhfb,
articleno = "14",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Su:2017:PJL,
author = "Che-Ping Su and Tuan-Fang Fan and Churn-Jung Liau",
title = "Possibilistic Justification Logic: Reasoning About
Justified Uncertain Beliefs",
journal = j-TOCL,
volume = "18",
number = "2",
pages = "15:1--15:??",
month = jun,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3091118",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Jun 23 17:25:24 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Justification logic originated from the study of the
logic of proofs. However, in a more general setting, it
may be regarded as a kind of explicit epistemic logic.
In such logic, the reasons a fact is believed are
explicitly represented as justification terms.
Traditionally, the modeling of uncertain beliefs is
crucially important for epistemic reasoning. Graded
modal logics interpreted with possibility theory
semantics have been successfully applied to the
representation and reasoning of uncertain beliefs;
however, they cannot keep track of the reasons an agent
believes a fact. This article is aimed at extending the
graded modal logics with explicit justifications. We
introduce a possibilistic justification logic, present
its syntax and semantics, and investigate its
metaproperties, such as soundness, completeness, and
realizability.",
acknowledgement = ack-nhfb,
articleno = "15",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Ponomaryov:2017:PDL,
author = "Denis Ponomaryov and Mikhail Soutchanski",
title = "Progression of Decomposed Local-Effect Action
Theories",
journal = j-TOCL,
volume = "18",
number = "2",
pages = "16:1--16:??",
month = jun,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3091119",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Jun 23 17:25:24 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "In many tasks related to reasoning about consequences
of a logical theory, it is desirable to decompose the
theory into a number of weakly related or independent
components. However, a theory may represent knowledge
that is subject to change, as a result of executing
actions that have effects on some of the initial
properties mentioned in the theory. Having once
computed a decomposition of a theory, it is
advantageous to know whether a decomposition has to be
computed again in the newly changed theory (obtained
from taking into account changes resulting from
execution of an action). In this article, we address
this problem in the scope of the situation calculus,
where a change of an initial theory is related to the
notion of progression. Progression provides a form of
forward reasoning; it relies on forgetting values of
those properties, which are subject to change, and
computing new values for them. We consider
decomposability and inseparability, two component
properties known from the literature, and contribute by
studying the conditions (1) when these properties are
preserved and (2) when they are lost wrt progression
and the related operation of forgetting. To show the
latter, we demonstrate the boundaries using a number of
negative examples. To show the former, we identify
cases when these properties are preserved under
forgetting and progression of initial theories in
local-effect basic action theories of the situation
calculus. Our article contributes to bridging two
different communities in knowledge representation,
namely, research on modularity and research on
reasoning about actions.",
acknowledgement = ack-nhfb,
articleno = "16",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}
@Article{Radcliffe:2017:UNF,
author = "Nicholas R. Radcliffe and Luis F. T. Moraes and Rakesh
M. Verma",
title = "Uniqueness of Normal Forms for Shallow Term Rewrite
Systems",
journal = j-TOCL,
volume = "18",
number = "2",
pages = "17:1--17:??",
month = jun,
year = "2017",
CODEN = "????",
DOI = "https://doi.org/10.1145/3060144",
ISSN = "1529-3785 (print), 1557-945X (electronic)",
ISSN-L = "1529-3785",
bibdate = "Fri Jun 23 17:25:24 MDT 2017",
bibsource = "http://www.acm.org/pubs/contents/journals/tocl/;
http://www.math.utah.edu/pub/tex/bib/tocl.bib",
abstract = "Uniqueness of normal forms (UN$^ = $ ) is an important
property of term rewrite systems. UN$^ = $ is decidable
for ground (i.e., variable-free) systems and
undecidable in general. Recently, it was shown to be
decidable for linear, shallow systems. We generalize
this previous result and show that this property is
decidable for shallow rewrite systems, in contrast to
confluence, reachability, and other related properties,
which are all undecidable for flat systems. We also
prove an upper bound on the complexity of our
algorithm. Our decidability result is optimal in a
sense, since we prove that the UN$^ = $ property is
undecidable for two classes of linear rewrite systems:
left-flat systems in which right-hand sides are of
height at most two and right-flat systems in which
left-hand sides are of height at most two.",
acknowledgement = ack-nhfb,
articleno = "17",
fjournal = "ACM Transactions on Computational Logic",
journal-URL = "http://portal.acm.org/browse_dl.cfm?idx=J773",
}