anchor.diff:  ! ---------------------------------------------------------------------------
   
   subroutine create_Hypre_grid(MPI_COMM_WORLD, hypre_grid, ilower, iupper, &
  -          num_procs, myid, ierr)
  +          num_procs, myid, nx, ny, ierr)
     implicit none
   
     integer,   intent(in)  :: MPI_COMM_WORLD
  
positive.code: 
  #ifdef useExtSolver
    call create_Hypre_grid(MPI_COMM_WORLD, hypre_grid, ilower, iupper, &
            num_procs, myid, ierr)
  #endif
  
  
  
negative.code:   integer,   intent(in)  :: iupper(0:num_procs-1,2)
    integer,   intent(in)  :: num_procs
    integer,   intent(in)  :: myid
    integer,   intent(in)  :: nx
    integer,   intent(in)  :: ny
    integer,   intent(out)  :: ierr
  
  #ifdef useExtSolver
  