A Process Calculus for Expressing Finite Place/Transition Petri Nets

We introduce the calculus Multi-CCS, which extends conservatively CCS with an operator of strong prefixing able to model atomic sequences of actions as well as multiparty synchronization. Multi-CCS is equipped with a labeled transition system semantics, which makes use of a minimal structural congruence. Multi-CCS is also equipped with an unsafe P/T Petri net semantics by means of a novel technique that generalizes Goltz's idea of using unsafe nets as semantic model to a language with restriction and strong prefixing. This is the first rich process calculus, including CCS as a subcalculus, which receives a semantics in terms of unsafe, labeled P/T nets. The main result of the paper is that a class of Multi-CCS processes, called {em finite-net processes}, is able to represent all finite (reduced) P/T nets.