anchor.diff:  
   ! ---------------------------------------------------------------------------
   
  -subroutine create_Hypre_A_vector(MPI_COMM_WORLD, hypre_grid, hypre_A, &
  +subroutine create_Hypre_A_matrix(MPI_COMM_WORLD, hypre_grid, hypre_A, &
             a, nx, ny, freesurfFac, dt, ierr)
     implicit none
   
  
positive.code: #endif
  
    return
  end subroutine create_Hypre_A_vector
  
  ! ---------------------------------------------------------------------------
  
  
negative.code:     ! 2*pi in this calculation
  #else
      ! use the external pressure solver
      call create_Hypre_A_matrix(MPI_COMM_WORLD, hypre_grid, hypre_A, &
            a, nx, ny, freesurfFac, dt, ierr)
  #endif
  
  