%%% -*-BibTeX-*-
%%% ====================================================================
%%%  BibTeX-file{
%%%     author          = "Nelson H. F. Beebe",
%%%     version         = "1.45",
%%%     date            = "05 May 2014",
%%%     time            = "17:58:25 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        = "15578 12861 64524 628784",
%%%     email           = "beebe at math.utah.edu, beebe at acm.org,
%%%                        beebe at computer.org (Internet)",
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%%%                        Computational Logic",
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%%%     docstring       = "This is a COMPLETE BibTeX bibliography for
%%%                        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.
%%%
%%%                        The journal has a World-Wide Web site at:
%%%
%%%                            http://www.acm.org/pubs/tocl
%%%                            http://tocl.acm.org
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%%%
%%%                            http://www.acm.org/pubs/contents/journals/tocl/
%%%                            http://portal.acm.org/browse_dl.cfm?idx=J773
%%%
%%%                        Qualified subscribers can retrieve the full
%%%                        text of recent articles in PDF form.
%%%
%%%                        At version 1.45, the COMPLETE journal
%%%                        coverage looked like this:
%%%
%%%                             2000 (  12)    2005 (  28)    2010 (  30)
%%%                             2001 (  21)    2006 (  24)    2011 (  21)
%%%                             2002 (  18)    2007 (  31)    2012 (  34)
%%%                             2003 (  21)    2008 (  22)    2013 (  34)
%%%                             2004 (  23)    2009 (  36)    2014 (  17)
%%%
%%%                             Article:        372
%%%
%%%                             Total entries:  372
%%%
%%%                        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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%%%                        family name of the first author or editor,
%%%                        year is a 4-digit number, and abbrev is a
%%%                        3-letter condensation of important title
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%%%
%%%                        In this bibliography, entries are sorted in
%%%                        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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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 B&uuml",
}

@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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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://doi.acm.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: -an O ( n ) precomputation phase building an index
                 structure, -followed by a phase enumerating the answers
                 with no repetition and a constant delay between two
                 consecutive outputs. 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 $-calculus",
  journal =      j-TOCL,
  volume =       "14",
  number =       "4",
  pages =        "31:1--31:??",
  month =        nov,
  year =         "2013",
  CODEN =        "????",
  DOI =          "http://dx.doi.org/10.1145/2528934",
  ISSN =         "1529-3785 (print), 1557-945X (electronic)",
  ISSN-L =       "1529-3785",
  bibdate =      "Tue Dec 3 18:27:46 MST 2013",
  bibsource =    "http://www.acm.org/pubs/contents/journals/tocl/;
                 http://www.math.utah.edu/pub/tex/bib/tocl.bib",
  abstract =     "We study confluence and the Church--Rosser property in
                 term rewriting and \lambda -calculus with explicit
                 bounds on term sizes and reduction lengths. Given a
                 system R, we are interested in the lengths of the
                 reductions in the smallest valleys t -{$>$} * s ' *
                 {$<$}- t ' expressed as a function: -for confluence a
                 function vs$_R$ ( m, n ) where the valleys are for
                 peaks t {$<$}- s -{$>$} * t ' with s of size at most m
                 and the reductions of maximum length n, and -for the
                 Church--Rosser property a function cvs$_R$ ( m, n )
                 where the valleys are for conversions t {$<$}-{$>$} * t
                 ' with t and t ' of size at most m and the conversion
                 of maximum length n. For confluent Term Rewriting
                 Systems (TRSs), we prove that vs$_R$ is a total
                 computable function, and for linear such systems that
                 cvs$_R$ is a total computable function. Conversely, we
                 show that every total computable function is the lower
                 bound on the functions vs$_R$ ( m, n ) and cvs$_R$ ( m,
                 n ) for some TRS R: In particular, we show that for
                 every total computable function \varphi : N -{$>$} N
                 there is a TRS R with a single term s such that vs$_R$
                 (| s |, n ) {$>$}= \varphi ( n ) and cvs$_R$ ( n, n )
                 {$>$}= \varphi ( n ) for all n. For orthogonal TRSs R
                 we prove that there is a constant k such that: (a)
                 vs$_R$ ( m, n ) is bounded from above by a function
                 exponential in k and (b) 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 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",
}