| 1. | This system follows the principle of intelligent , open , hierarchical and specialized , utilizing knowledge furthest . here , knowledge contains parameters library , shapes library , rules library and human assistance . in this system , we define a pattern description language to describe shapes based on line we also define line ' s attributes and operations 系统中定义了一个模式语言描述,以线为基础来描述图形,并定义了图形的属性和运算,为该类图形提供了一个高效的描述工具。 |