Purpose
 =======
 
    LA_SYSV computes the solution to a linear system of equations
 A*X = B, where A is a real or complex symmetric matrix and X and B are
 rectangular matrices or vectors. A diagonal pivoting method is used to
 factor A as
      A = U*D*U^T if UPLO = 'U', or A = L*D*L^T if UPLO = 'L'
 where U (or L) is a product of permutation and unit upper (or lower)
 triangular matrices, and D is a symmetric block diagonal matrix with 
 1 by 1 and 2 by 2 diagonal blocks. The factored form of A is then used
 to solve the above system.
    LA_HESV computes the solution to a linear system of equations 
 A*X = B, where A is a complex Hermitian matrix and X and B are 
 rectangular matrices or vectors. A diagonal pivoting method is used to
 factor A as
      A = U*D*U^H if UPLO = 'U', or A = L*D*L^H if UPLO = 'L'
 where U (or L) is a product of permutation and unit upper (or lower)
 triangular matrices, and D is a complex Hermitian block diagonal
 matrix with 1 by 1 and 2 by 2 diagonal blocks. The factored form of A
 is then used to solve the above system.
 
 =========
 
          SUBROUTINE LA_SYSV / LA_HESV( A, B, UPLO=uplo, &
 	                            IPIV=ipiv, INFO=info )
                <type>(<wp>), INTENT(INOUT) :: A(:,:), <rhs>
                CHARACTER(LEN=1), INTENT(IN), OPTIONAL :: UPLO
                INTEGER, INTENT(OUT), OPTIONAL :: IPIV(:)
                INTEGER, INTENT(OUT), OPTIONAL :: INFO
          where
                <type> ::= REAL | COMPLEX
                <wp>   ::= KIND(1.0) | KIND(1.0D0)
                <rhs>  ::= B(:,:) | B(:)
 
 Arguments
 =========
 
 A      (input/output) REAL or COMPLEX square array, shape (:,:).
        On entry, the matrix A.
        If UPLO = 'U', the upper triangular part of A contains the upper
        triangular part of the matrix A, and the strictly lower 
        triangular part of A is not referenced.
        If UPLO = 'L', the lower triangular part of A contains the lower 
        triangular part of the matrix A, and the strictly upper 
        triangular part of A is not referenced.
        On exit, the block diagonal matrix D and the multipliers used to
        obtain the factor U or L from the factorization of A.
 B      (input/output) REAL or COMPLEX array, shape (:,:) with 
        size(B,1) = size(A,1) or shape (:) with size(B) = size(A,1).
        On entry, the matrix B.
        On exit, the solution matrix X.
 UPLO   Optional (input) CHARACTER(LEN=1)
          = 'U': Upper triangle of A is stored;
          = 'L': Lower triangle of A is stored.
        Default value: 'U'.
 IPIV   Optional (output) INTEGER array, shape (:) with size(IPIV) = 
        size(A,1).
        Details of the row and column interchanges and the block 
        structure of D.
        If IPIV(k) > 0, then rows and columns k and IPIV(k) were
        interchanged, and D(k,k) is a 1 by 1 diagonal block.
        If IPIV k < 0, then there are two cases:
         1. If UPLO = 'U' and IPIV(k) = IPIV(k-1) < 0, then rows and 
 	   columns (k-1) and -IPIV(k) were interchanged and 
 	   D(k-1:k,k-1:k) is a 2 by 2 diagonal block.
         2. If UPLO = 'L' and IPIV(k) = IPIV(k+1) < 0, then rows and
 	   columns (k + 1) and -IPIV(k) were interchanged and 
 	   D(k:k+1,k:k+1) is a 2 by 2 diagonal block.
 INFO   Optional (output) INTEGER
        = 0: successful exit.
        < 0: if INFO = -i, the i-th argument had an illegal value.
        > 0: if INFO = i, D(i,i) = 0. The factorization has been 
             completed, but the block diagonal matrix D is singular, so
 	    the solution could not be computed.
        If INFO is not present and an error occurs, then the program is
        terminated with an error message.