anchor.diff:    ! Check some stuff out.
     call handle_err(nf90_inquire(ncid, ndims, nvars, ngatts, unlimdimid, file_format))
     if (ndims /= 2 .or. nvars /= 1 .or. ngatts /= 0 .or. unlimdimid /= -1 .or. &
  -       file_format /= nf90_format_netcdf4_classic) stop 2
  +       file_format /= nf90_format_netcdf4_classic) stop 3
   
     call handle_err(nf90_inquire_variable(ncid, varid, name_in, xtype_in, ndims, dimids_in, &
          natts_in, contiguous_in, chunksizes_in, deflate_level_in, shuffle_in, fletcher32_in, &
  
positive.code:   dimids =  (/ y_dimid, x_dimid /)
  
    ! Define the variable. 
    chunksizes = (/ 256, 256 /)
    call handle_err(nf90_def_var(ncid, 'data', NF90_INT, dimids, & 
         varid, chunksizes = chunksizes, deflate_level = 4))
  
  
negative.code:        natts_in .ne. 0 .or. contiguous_in .neqv. .false. .or. &
         chunksizes_in(1) /= chunksizes(1) .or. chunksizes_in(2) /= chunksizes(2) .or. &
         deflate_level_in .ne. 4 .or. shuffle_in .neqv. .false. .or. fletcher32_in .neqv. .false.) &
         stop 4
  
    ! Check the data.
    call handle_err(nf90_get_var(ncid, varid, data_in))
  