Mobile Petri nets

We add mobility to Place-Transition Petri Nets: tokens are names for places, and an input token of a transition can be used in its postset to specify a destination. Mobile Petri Nets are then further extended to Dynamic Nets, by adding the possibility of creating new nets during the firing of a transition. In this way, starting from Petri Nets, we define a simple hierarchy of nets with increasing degrees of dynamicity. For each class in this hierarchy we provide its encoding in the former class. Our work has been largely inspired by the join-calculus of Fournet and Gonthier, that turns out to be a (well motivated) particular case of Dynamic Petri Nets. The main difference is that, in the preset of a transition, we allow for both non-linear patterns (name unification) and (locally) free names for input places (i.e. we remove the locality constraint, and preserve reflexion)