Bounded Reachability Checking of Asynchronous Systems Using Decision Diagrams

Abstract

Bounded reachability or model checking is widely believed to work poorly when using decision diagrams instead of SAT procedures. Recent research suggests this to be untrue with regards to synchronous systems, particularly digital circuits. This paper shows that the belief is also a myth for asynchronous systems, such as models specified by Petri nets. We propose Bounded Saturation, a new algorithm to compute bounded state spaces using Multi-way Decision Diagrams (MDDs). This is based on the established Saturation algorithm which benefits from a non-standard search strategy that is very different from breadth-first search. To bound Saturation, we employ Edge-Valued MDDs and rework its search strategy. Experimental results show that our algorithm often, but not always, compares favorably against two SAT-based approaches advocated in the literature for deadlock checking in Petri nets.