Token-Free Petri Nets

Abstract

In the paper a modification of classical Petri nets is defined. The fundamental notions of nets, as places, transitions, and firing rules are retained. In this way the composition properties of classical nets as well as their full expressive power is preserved. However, while preserving basic notions of Petri nets theory, the presented modification offers much more freedom in defining data types and the way of place contents transformations. It turns out that such a modification leads to a simplification of the net description (neither tokens nor arrows are necessary anymore) and yet strengthening its expressive power.