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NAME
     ctrsyl - solve the complex Sylvester matrix equation

SYNOPSIS
     SUBROUTINE CTRSYL( TRANA, TRANB, ISGN, M, N, A, LDA, B, LDB,
               C, LDC, SCALE, INFO )

     CHARACTER TRANA, TRANB

     INTEGER INFO, ISGN, LDA, LDB, LDC, M, N

     REAL SCALE

     COMPLEX A( LDA, * ), B( LDB, * ), C( LDC, * )



     #include <sunperf.h>

     void ctrsyl(char trana, char tranb, int isgn, int m, int  n,
               complex  *ca,  int lda, complex *cb, int ldb, com-
               plex *cc, int ldc, float *sscale, int *info) ;

PURPOSE
     CTRSYL solves the complex Sylvester matrix equation:

        op(A)*X + X*op(B) = scale*C or
        op(A)*X - X*op(B) = scale*C,

     where op(A) = A or A**H, and A and B are both upper triangu-
     lar.  A is M-by-M and B is N-by-N; the right hand side C and
     the solution X are M-by-N; and scale is an output scale fac-
     tor, set <= 1 to avoid overflow in X.


ARGUMENTS
     TRANA     (input) CHARACTER*1
               Specifies the option op(A):
               = 'N': op(A) = A    (No transpose)
               = 'C': op(A) = A**H (Conjugate transpose)

     TRANB     (input) CHARACTER*1
               Specifies the option op(B):
               = 'N': op(B) = B    (No transpose)
               = 'C': op(B) = B**H (Conjugate transpose)

     ISGN      (input) INTEGER
               Specifies the sign in the equation:
               = +1: solve op(A)*X + X*op(B) = scale*C
               = -1: solve op(A)*X - X*op(B) = scale*C

     M         (input) INTEGER
               The order of the matrix A, and the number of  rows
               in the matrices X and C. M >= 0.

     N         (input) INTEGER
               The order of the  matrix  B,  and  the  number  of
               columns in the matrices X and C. N >= 0.

     A         (input) COMPLEX array, dimension (LDA,M)
               The upper triangular matrix A.

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

     B         (input) COMPLEX array, dimension (LDB,N)
               The upper triangular matrix B.

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

     C         (input/output) COMPLEX array, dimension (LDC,N)
               On entry, the M-by-N right hand side matrix C.  On
               exit, C is overwritten by the solution matrix X.

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

     SCALE     (output) REAL
               The scale factor, scale, set <= 1 to  avoid  over-
               flow in X.

     INFO      (output) INTEGER
               = 0: successful exit
               < 0: if INFO = -i, the i-th argument had an  ille-
               gal value
               = 1: A and B have  common  or  very  close  eigen-
               values;  perturbed  values  were used to solve the
               equation (but the matrices A and B are unchanged).

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