subroutine rscsl (lftblk, array, nrwblk, nbloks, rgtblk,
     *                  b, pivot, nparts, work)
c
      double precision lftblk(1), array(1), rgtblk(1), b(1), work(1)
      integer nrwblk, nbloks, pivot(1), nparts
c    ***----------------------------------------------------------***
c    *   Given the factors of ABD matrix A computed by subroutine   *
c    *   'rscfa' and stored in arrays lftblk, array, rgtblk,        *
c    *   work and pivot, this subroutine solves the linear system   *
c    *   A x = b.  b is overwritten with x.  See comments in        *
c    *   subroutine 'rscale' for further details.                   *
c    ***----------------------------------------------------------***
         integer nsquar, wk1, wk2, wk3, wk4, minblk, remblk
c    ***----------------------------------------------------------***
c    *      Work-space allocation:                                  *
c    *         right blocks             -   work(1)..work(wk2-1)    *
c    *         1st-level product blocks - work(wk2)..work(wk3-1)    *
c    *         2nd-level product block  - work(wk3)..work(wk4-1)    *
c    *         local storage for BLAS   - work(wk4)..end            *
c    *                                                              *
c    *      Total requirement:  nbloks*[nrwblkxnrwblk]              *
c    *                        + nparts*[nrwblkxnrwblk]              *
c    *                        +        [nrwblkxnrwblk]              *
c    *                        + nparts*[nrwblkxnrwblk]              *
c    ***----------------------------------------------------------***
         nsquar = nrwblk**2
         wk1 = 1
         wk2 = wk1 + nbloks*nsquar
         wk3 = wk2 + nparts*nsquar
         wk4 = wk3 + nsquar
c    ***----------------------------------------------------------***
c    *      Calculate minimum number of blocks per partition        *
c    *      Remaining blocks are distributed evenly among the       *
c    *      first partitions.                                       *
c    ***----------------------------------------------------------***
         minblk = nbloks/nparts
         remblk = nbloks - minblk*nparts
c    ***----------------------------------------------------------***
c    *      Three level forward elimination.                        *
c    ***----------------------------------------------------------***
         call rscsf1(array,work(wk1),nrwblk,b,
     *               pivot,minblk,remblk,nparts,work(wk4))
         call rscsf2(array,work(wk1),work(wk2),nrwblk,b,
     *               pivot,minblk,remblk,nparts,work(wk4))
         call rscsf3(lftblk,array,work(wk1),nrwblk,rgtblk,
     *               b,b,pivot,minblk,remblk,nparts,work(wk4))
c    ***----------------------------------------------------------***
c    *      Three level back-solve.                                 *
c    ***----------------------------------------------------------***
         call rscsb3(array,work(wk1),work(wk2),work(wk3),
     *               nrwblk,nbloks,b,b,pivot,nparts,work(wk4))
         call rscsb2(array,work(wk2),nrwblk,b,
     *               minblk,remblk,nparts,work(wk4))
         call rscsb1(array,nrwblk,b,
     *               minblk,remblk,nparts,work(wk4))
      return
      end