Petri Net Based CTL Model Checking: Using a New Method to Construct OBDD Variable Order

This paper proposes a new heuristic method to quickly construct OBDD variable order for Petri net based CTL model checking. Consequently, OBDDs using these orders have a good compressing effect for modular and loosely-coupled Petri nets. For further enhancing the performance of our model checking, we apply a model checking strategy: when producing the reachability graph of a Petri net, we only store its states encoded by an OBDD but not any state transition since the number of state transitions is generally much greater than the number of states themselves; while computing the set of satisfiable states of a CTL formula, we utilize these states and the structure of the Petri net to do so. Consequently, this strategy can generally improve space and time efficiency of model checking. A number of experiments show the effectiveness of our method. For example, our method can verify deadlocks of Dining Philosophers Problem for the case of 5000 philosophers in 12 hours, which has about 10
³³⁰⁰
states.