deferred class CMD_INST_STONE inherit STONE redefine data end feature -- Command type features stone_type: INTEGER is do Result := Stone_types.instance_type end; process (hole: HOLE) is -- Process Current stone dropped in hole `hole'. do hole.process_instance (Current) end; stone_cursor: SCREEN_CURSOR is do Result := Cursors.command_instance_cursor end; associated_command: CMD is -- Command type associated -- with current instance deferred end; feature -- Command instance features data: CMD_INSTANCE is deferred end; end