Augmented reachability trees for 1-place-unbounded generalized Petri nets

An augmented reachability tree (ART) is proposed to extend the capability of the classical reachability tree (RT) for analyzing qualitative properties, such as liveness, of a class of unbounded generalized Petri nets, called 1-place-unbounded nets, where there is at most one unbounded place for each net. The idea is based on the computation of the minimal marking of each node in the tree. An algorithm for obtaining the minimal marking is shown. Examples are given to illustrate the technique. In addition to liveness, the proposed method can verify other properties such as reversibility and feasible firing sequences. Furthermore, properties verifiable by RT are also verifiable by ART.