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NAME
     zunm2l - overwrite the general complex m-by-n matrix C  with
     Q  *  C  if SIDE = 'L' and TRANS = 'N', or   Q'* C if SIDE =
     'L' and TRANS = 'C', or   C * Q if SIDE = 'R'  and  TRANS  =
     'N', or   C * Q' if SIDE = 'R' and TRANS = 'C',

SYNOPSIS
     SUBROUTINE ZUNM2L( SIDE, TRANS, M, N, K,  A,  LDA,  TAU,  C,
               LDC, WORK, INFO )

     CHARACTER SIDE, TRANS

     INTEGER INFO, K, LDA, LDC, M, N

     COMPLEX*16 A( LDA, * ), C( LDC, * ), TAU( * ), WORK( * )



     #include <sunperf.h>

     void zunm2l(char side, char trans, int  m,  int  n,  int  k,
               doublecomplex  *za,  int  lda, doublecomplex *tau,
               doublecomplex *zc, int ldc, int *info) ;

PURPOSE
     ZUNM2L overwrites the general complex m-by-n matrix C with

     where Q is a complex unitary matrix defined as  the  product
     of k elementary reflectors

           Q = H(k) . . . H(2) H(1)

     as returned by ZGEQLF. Q is of order m if SIDE = 'L' and  of
     order n if SIDE = 'R'.


ARGUMENTS
     SIDE      (input) CHARACTER*1
               = 'L': apply Q or Q' from the Left
               = 'R': apply Q or Q' from the Right

     TRANS     (input) CHARACTER*1
               = 'N': apply Q  (No transpose)
               = 'C': apply Q' (Conjugate transpose)

     M         (input) INTEGER
               The number of rows of the matrix C. M >= 0.

     N         (input) INTEGER
               The number of columns of the matrix C. N >= 0.

     K         (input) INTEGER
               The number of elementary reflectors whose  product
               defines the matrix Q.  If SIDE = 'L', M >= K >= 0;
               if SIDE = 'R', N >= K >= 0.

     A         (input) COMPLEX*16 array, dimension (LDA,K)
               The i-th column  must  contain  the  vector  which
               defines  the  elementary  reflector  H(i), for i =
               1,2,...,k, as returned by ZGEQLF  in  the  last  k
               columns of its array argument A.  A is modified by
               the routine but restored on exit.

     LDA       (input) INTEGER
               The leading dimension of the array A.  If  SIDE  =
               'L',  LDA  >=  max(1,M);  if  SIDE  =  'R', LDA >=
               max(1,N).

     TAU       (input) COMPLEX*16 array, dimension (K)
               TAU(i) must contain the scalar factor of the  ele-
               mentary reflector H(i), as returned by ZGEQLF.

     C         (input/output) COMPLEX*16 array, dimension (LDC,N)
               On entry, the m-by-n matrix  C.   On  exit,  C  is
               overwritten by Q*C or Q'*C or C*Q' or C*Q.

     LDC       (input) INTEGER
               The leading dimension  of  the  array  C.  LDC  >=
               max(1,M).

     WORK      (workspace) COMPLEX*16 array, dimension
               (N) if SIDE = 'L', (M) if SIDE = 'R'

     INFO      (output) INTEGER
               = 0: successful exit
               < 0: if INFO = -i, the i-th argument had an  ille-
               gal value

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