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NAME

       PZDBTRF  -  compute  a  LU  factorization  of  an N-by-N complex banded
       diagonally dominant-like distributed matrix with bandwidth BWL, BWU

SYNOPSIS

       SUBROUTINE PZDBTRF( N, BWL, BWU, A, JA, DESCA, AF,  LAF,  WORK,  LWORK,
                           INFO )

           INTEGER         BWL, BWU, INFO, JA, LAF, LWORK, N

           INTEGER         DESCA( * )

           COMPLEX*16      A( * ), AF( * ), WORK( * )

PURPOSE

       PZDBTRF  computes  a  LU  factorization  of  an  N-by-N  complex banded
       diagonally dominant-like distributed matrix with  bandwidth  BWL,  BWU:
       A(1:N,  JA:JA+N-1).   Reordering is used to increase parallelism in the
       factorization.  This reordering results in factors that  are  DIFFERENT
       from  those  produced  by  equivalent  sequential  codes. These factors
       cannot be used directly by users; however, they can be used in
       subsequent calls to PZDBTRS to solve linear systems.

       The factorization has the form

               P A(1:N, JA:JA+N-1) P^T = L U

       where U is a banded upper triangular  matrix  and  L  is  banded  lower
       triangular, and P is a permutation matrix.