The representations include Process Controlling Trees (PCT), Data Direction Graphs (DDG), and Defined Behavior Graphs (DBG), which express control structure, data relation, and circuit behavior of processes respectively.

• 通过抽象,本文将进程中语句的控制结构表示为“进程控制树”,将其中数据关系表示为“数据流向图”,且将其定义的电路行为表示成“定义行为图”。