Continuous Petri Nets: Expressive Power and Decidability Issues

State explosion is a fundamental problem in the analysis and synthesis of discrete event systems. Continuous Petri nets can be seen as a relaxation of discrete models. The expected gains are twofold: improvements in comlexity and in decidability. This paper concentrates on the study of decidability issues. In the case of autonomous nets it is proved that properties like reachability, liveness or deadlock-freeness remain decidable. When time is introduced in the model (using an infinite server semantics) decidability of these properties is lost, since continuous timed Petri nets are able to simulate Turing machines.