anchor.diff:          use aot_table_module, only: aot_table_top, aot_get_val, aot_exists
   
           use errors, only: stop_all
  +        use parallel, only: nprocs
           use restart_hdf5, only: restart_info_t, init_restart_info_t, redistribute_restart_hdf5
   
           integer(c_int) :: nresult
  
positive.code: 
          ! Lua:
          !    redistribute {
          !       nprocs = N, -- required
          !       read = id,
          !       write = id,
          !    }
  
negative.code:         lua_state = flu_copyptr(l)
          opts = aot_table_top(lua_state)
  
          call aot_get_val(nprocs_target, err, lua_state, opts, 'nprocs', default=nprocs)
  
          read_exists = aot_exists(lua_state, opts, 'read')
          write_exists = aot_exists(lua_state, opts, 'write')
  