CGTSV(l)		LAPACK routine (version	1.1)		     CGTSV(l)

NAME
  CGTSV	- solve	the equation   A*X = B,

SYNOPSIS

  SUBROUTINE CGTSV( N, NRHS, DL, D, DU,	B, LDB,	INFO )

      INTEGER	    INFO, LDB, N, NRHS

      COMPLEX	    B( LDB, * ), D( * ), DL( * ), DU( *	)

PURPOSE
  CGTSV	 solves	the equation

  where	A is an	N-by-N tridiagonal matrix, by Gaussian elimination with	par-
  tial pivoting.

  Note that the	equation  A'*X = B  may	be solved by interchanging the order
  of the arguments DU and DL.

ARGUMENTS

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

  NRHS	  (input) INTEGER
	  The number of	right hand sides, i.e.,	the number of columns of the
	  matrix B.  NRHS >= 0.

  DL	  (input/output) COMPLEX array,	dimension (N-1)
	  On entry, DL must contain the	(n-1) subdiagonal elements of A.  On
	  exit,	DL is overwritten by the (n-2) elements	of the second super-
	  diagonal of the upper	triangular matrix U from the LU	factorization
	  of A,	in DL(1), ..., DL(n-2).

  D	  (input/output) COMPLEX array,	dimension (N)
	  On entry, D must contain the diagonal	elements of A.	On exit, D is
	  overwritten by the n diagonal	elements of U.

  DU	  (input/output) COMPLEX array,	dimension (N-1)
	  On entry, DU must contain the	(n-1) superdiagonal elements of	A.
	  On exit, DU is overwritten by	the (n-1) elements of the first
	  superdiagonal	of U.

  B	  (input/output) COMPLEX array,	dimension (LDB,NRHS)
	  On entry, the	N-by-NRHS right	hand side matrix B.  On	exit, if INFO
	  = 0, the N-by-NRHS solution matrix X.

  LDB	  (input) INTEGER
	  The leading dimension	of the array B.	 LDB >=	max(1,N).

  INFO	  (output)
	  = 0:	successful exit
	  < 0:	if INFO	= -i, the i-th argument	had an illegal value
	  > 0:	if INFO	= i, U(i,i) is exactly zero, and the solution has not
	  been computed.  The factorization has	not been completed unless i =
	  N.