 
      SUBROUTINE DNBSL(ABE,LDA,N,ML,MU,IPVT,B,JOB)
C***BEGIN PROLOGUE  DNBSL
C***DATE WRITTEN   800728   (YYMMDD)
C***REVISION DATE  820801   (YYMMDD)
C***CATEGORY NO.  D2A2
C***KEYWORDS  BAND,DOUBLE PRECISION,LINEAR EQUATIONS,NONSYMMETRIC
C***AUTHOR  VOORHEES, E., (LANL)
C***PURPOSE  Solves a double precision BAND system using
C            the factors computed by DNBCO or DNBFA.
C***DESCRIPTION
C
C     DNBSL solves the double precision band system
C     A * X = B  or  TRANS(A) * X = B
C     using the factors computed by DNBCO or DNBFA.
C
C     On Entry
C
C        ABE     DOUBLE PRECISION(LDA, NC)
C                the output from DNBCO or DNBFA.
C                NC must be .GE. 2*ML+MU+1 .
C
C        LDA     INTEGER
C                the leading dimension of the array  ABE .
C
C        N       INTEGER
C                the order of the original matrix.
C
C        ML      INTEGER
C                number of diagonals below the main diagonal.
C
C        MU      INTEGER
C                number of diagonals above the main diagonal.
C
C        IPVT    INTEGER(N)
C                the pivot vector from DNBCO or DNBFA.
C
C        B       DOUBLE PRECISION(N)
C                the right hand side vector.
C
C        JOB     INTEGER
C                = 0         to solve  A*X = B .
C                = nonzero   to solve  TRANS(A)*X = B , where
C                            TRANS(A)  is the transpose.
C
C     On Return
C
C        B       the solution vector  X .
C
C     Error Condition
C
C        A division by zero will occur if the input factor contains a
C        zero on the diagonal.  Technically this indicates singularity
C        but it is often caused by improper arguments or improper
C        setting of LDA.  It will not occur if the subroutines are
C        called correctly and if DNBCO has set RCOND .GT. 0.0
C        or DNBFA has set INFO .EQ. 0 .
C
C     To compute  INVERSE(A) * C  where  C  is a matrix
C     with  P  columns
C           CALL DNBCO(ABE,LDA,N,ML,MU,IPVT,RCOND,Z)
C           IF (RCOND is too small) GO TO ...
C           DO 10 J = 1, P
C             CALL DNBSL(ABE,LDA,N,ML,MU,IPVT,C(1,J),0)
C        10 CONTINUE
C
C     SLATEC.  This version dated 07/28/80 .
C     E. A. Voorhees, Los Alamos Scientific Laboratory
C
C     Subroutines and Functions
C
C      DAXPY,DDOT
C     Fortran  MIN0
C***REFERENCES  SUBROUTINE DNBSL WAS DEVELOPED BY GROUP C-3, LOS ALAMOS
C                 SCIENTIFIC LABORATORY, LOS ALAMOS, NM 87545.
C***ROUTINES CALLED  DAXPY,DDOT
C***END PROLOGUE  DNBSL
 
 
