Petri网的进程文法和进程语言

一、引言 Petri网进程是分析网系统运行行为最有力的工具。Petri网进程既考虑了网系统的状态变化又准确记录了引起这些变化的条件,清晰地反映事件(变迁)之间的并发和顺序关系,因此,Petri网进程比其它分析方法更便于对并发现象以及系统中同并发有关的一些性质进行分析。然而,Petri网的一个进程只能反映Petri网的一种可能的运行情况。一个Petri网往往有许多个进程,不可能一一列举,这就为进程分析带来了困难。文1,2]中,提出了利用进程表达式描述Petri网的所有进程的方法,一个有界Petri网的进程表达式是该网的基本子进程集(有限集)为字母表的正规表达式,一个无界公平Petri网在可重复进程段行为等价的条件下也是一个正规表达式。对

Process Grammar and Process Language of Petri Nets

The concept of process grammar, based on the idea of vector grammar, for petri net is presented in this pa-per. The process language of a petri net can be generated by derivation according to its process grammar . The set ofbasic process section sequence represented by the process language of a petri net ∑is the same as that represented bythe process expression of ∑if ∑is bounded or fair. In the case of that∑is unbounded and unfair ,the set of all processof∑ can also be represented by its process language passed through parallel processing.