PDPTTRSV - solve a tridiagonal triangular system of linear equations A(1:N, JA:JA+N-1) * X =

       PDPTTRSV  -  solve  a  tridiagonal  triangular  system  of  linear  equations    A(1:N,  JA:JA+N-1) * X =
       B(IB:IB+N-1, 1:NRHS)

       PDPTTRSV solves a tridiagonal triangular system of linear equations
                                      or
                           A(1:N, JA:JA+N-1)^T * X = B(IB:IB+N-1, 1:NRHS)

       where A(1:N, JA:JA+N-1) is a tridiagonal
       triangular matrix factor produced by the
       Cholesky factorization code PDPTTRF
       and is stored in A(1:N,JA:JA+N-1) and AF.
       The matrix stored in A(1:N, JA:JA+N-1) is either
       upper or lower triangular according to UPLO,
       and the choice of solving A(1:N, JA:JA+N-1) or A(1:N,  JA:JA+N-1)^T  is  dictated  by  the  user  by  the
       parameter TRANS.

       Routine PDPTTRF MUST be called first.

LAPACK version 1.5                                 12 May 1997                                       PDPTTRSV(l)

       SUBROUTINE PDPTTRSV( UPLO, N, NRHS, D, E, JA, DESCA, B, IB, DESCB, AF, LAF, WORK, LWORK, INFO )

           CHARACTER        UPLO

           INTEGER          IB, INFO, JA, LAF, LWORK, N, NRHS

           INTEGER          DESCA( * ), DESCB( * )

           DOUBLE           PRECISION AF( * ), B( * ), D( * ), E( * ), WORK( * )