Petri网系统中变迁的分级活性判定

Determination of the Hierarchy Liveness of Transitions in Petri net Systems

活性(liveness)是Petri网的基本性质之一。从Petri网系统的有效(受控)可重复向量出发,给出一般Petri网系统中变迁为2级活或是3级活的判定依据。对于一个变迁t而言,t是二级活的,当且仅当存在一个有效(受控)可重复向量X,X有一个分量大于零;t是三级活的,当且仅当存在一个有效可重复向量X,X有一个分量大于零。最后,用实例说明判断方法的可使用性。

Liveness is one of the basic properties of Petri nets,while the liveness of transitions in Petri net systems can be divided into four levels.Based of the effective(controlled) and repetitive vectors,this paper proposes criteria for judging the transitions to be second level live,or third level live in Petri nets.Finally,the usefulness of the methodology is illustrated with an exact sample.