Causality Semantics of Petri Nets with Weighted Inhibitor Arcs

A causality semantics for weighted Place/Transition nets with weighted inhibitor arcs (PTI-nets) is proposed, by extending the standard approach based on the process semantics given through net unfolding and occurrence nets. It is demonstrated how processes corresponding to step sequences of PTI-nets can be constructed, and a nonalgorithmic (axiomatic) characterisation is given of the processes that can be obtained in this way. Moreover, a framework is established allowing to separately consider behaviours, processes and causality, in order to facilitate the discussion of their mutual consistency for different Petri net classes.