ZSPTRI(l)		LAPACK routine (version	1.1)		    ZSPTRI(l)

NAME
  ZSPTRI - compute the inverse of a complex symmetric indefinite matrix	A in
  packed storage using the factorization A = U*D*U**T or A = L*D*L**T com-
  puted	by ZSPTRF

SYNOPSIS

  SUBROUTINE ZSPTRI( UPLO, N, AP, IPIV,	WORK, INFO )

      CHARACTER	     UPLO

      INTEGER	     INFO, N

      INTEGER	     IPIV( * )

      COMPLEX*16     AP( * ), WORK( * )

PURPOSE
  ZSPTRI computes the inverse of a complex symmetric indefinite	matrix A in
  packed storage using the factorization A = U*D*U**T or A = L*D*L**T com-
  puted	by ZSPTRF.

ARGUMENTS

  UPLO	  (input) CHARACTER*1
	  Specifies whether the	details	of the factorization are stored	as an
	  upper	or lower triangular matrix.  = 'U':  Upper triangular, form
	  is A = U*D*U**T;
	  = 'L':  Lower	triangular, form is A =	L*D*L**T.

  N	  (input) INTEGER
	  The order of the matrix A.  N	>= 0.

  AP	  (input/output) COMPLEX*16 array, dimension (N*(N+1)/2)
	  On entry, the	block diagonal matrix D	and the	multipliers used to
	  obtain the factor U or L as computed by ZSPTRF, stored as a packed
	  triangular matrix.

	  On exit, if INFO = 0,	the (symmetric)	inverse	of the original
	  matrix, stored as a packed triangular	matrix.	The j-th column	of
	  inv(A) is stored in the array	AP as follows: if UPLO = 'U', AP(i +
	  (j-1)*j/2) = inv(A)(i,j) for 1<=i<=j;	if UPLO	= 'L', AP(i + (j-
	  1)*(2n-j)/2) = inv(A)(i,j) for j<=i<=n.

  IPIV	  (input) INTEGER array, dimension (N)
	  Details of the interchanges and the block structure of D as deter-
	  mined	by ZSPTRF.

  WORK	  (workspace) COMPLEX*16 array,	dimension (N)

  INFO	  (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 matrix is singular and its
	  inverse could	not be computed.