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NAME
     dsytrs - solve a system of linear equations A*X = B  with  a
     real symmetric matrix A using the factorization A = U*D*U**T
     or A = L*D*L**T computed by DSYTRF

SYNOPSIS
     SUBROUTINE DSYTRS( UPLO, N, NRHS, A, LDA, IPIV, B, LDB, INFO
               )

     CHARACTER UPLO

     INTEGER INFO, LDA, LDB, N, NRHS

     INTEGER IPIV( * )

     DOUBLE PRECISION A( LDA, * ), B( LDB, * )



     #include <sunperf.h>

     void dsytrs(char uplo, int n, int nrhs, double *da, int lda,
               int *ipivot, double *db, int ldb, int *info) ;

PURPOSE
     DSYTRS solves a system of linear equations A*X =  B  with  a
     real symmetric matrix A using the factorization A = U*D*U**T
     or A = L*D*L**T computed by DSYTRF.


ARGUMENTS
     UPLO      (input) CHARACTER*1
               Specifies whether the details of the factorization
               are stored as an upper or lower triangular matrix.
               = 'U':  Upper triangular, form is A = U*D*U**T;
               = 'L':  Lower triangular, form is A = L*D*L**T.

     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.

     A         (input) DOUBLE PRECISION array, dimension (LDA,N)
               The block diagonal matrix D  and  the  multipliers
               used  to  obtain  the factor U or L as computed by
               DSYTRF.

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

     IPIV      (input) INTEGER array, dimension (N)
               Details of the interchanges and the  block  struc-
               ture of D as determined by DSYTRF.

     B         (input/output) DOUBLE PRECISION  array,  dimension
               (LDB,NRHS)
               On entry, the right hand side matrix B.  On  exit,
               the solution matrix X.

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

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

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