The above separating idea keeps the integrality of diagram structure, breaking up the wholes into parts simplifies the design and prepares for the realization of transforming the ladder diagram into STL from the angle of AOV diagram.

• 所提出的依据图的拓扑关系划分链表的思想,保持了图结构的完整性,将梯形图化整为零处理,简化了程序设计,为从图的角度研究梯形图向语句表的转化打下基础。