Structural Place Invariants for Analyzing the Behavioral Properties of Nested Petri Nets
Nested Petri nets (NP-nets) is an extension of the Petri nets formalism within the “nets-within-nets” approach. Due to tokens with individual behavior and the mechanism of synchronization NP-nets are convenient for modeling multi-agent and adaptive systems, flexible workflow nets, and other systems with mobile interacting components and dynamic structure. In contrast to classical Petri nets, there is still a lack of analysis methods for NP-nets. In this paper we show, that the classical Petri nets analysis technique based on place invariants can be extended to NP-nets. This paper defines place invariants of NP-nets, which link several NP-net components and allow to prove crucial behavioral properties directly from the NP-net structure. An algorithm for computing NP-net invariants is presented and illustrated with an example of EJB system verification.