Axioms for contextual net processes

Abstract

In the classical theory of Petri nets, a process is an operational description of the behaviour of a net, which takes into account the causal links between transitions in a sequence of firing steps. In the categorical framework developed in [19,11], processes of a P/T net are modeled as arrows of a suitable monoidal category: In this paper we lay the basis of a similar characterization for contextual P/T nets, that is, P/T nets extended with read arcs, which allows a transition to check for the presence of a token in a place, without consuming it.

Research partly supported by the EC TMR Network GETGRATS (General Theory of Graph Transformation Systems) through the Technical University of Berlin and the University of Pisa; by the Office of Naval Information Research Contracts N00014-95-C-0225 and N00014-96-C-0114; by the National Science Foundation Grant CCR-9633363; by the U.S. Army Contract DABT63-96-C-0096 (DARPA); and by the Information Technology Promotion Agency, Japan, as part of the Industrial Science and Technology Frontier Program “New Models for Software Architecture” sponsored by NEDO (New Energy and Industrial Technology Development Organization). Research carried out in part while the second author was on leave at Computer Science Laboratory, SRI International, Menlo Park, USA, and visiting scholar at Stanford University