Symbolic Semantics Revisited

Symbolic bisimulations were introduced as a mean to define value-passing process calculi using smaller, possibly finite labelled transition systems, equipped with symbolic actions. Similar ideas have been used for modeling with fewer transitions the input behavior of open and asynchronous π-calculus. In this paper we generalize the symbolic technique and apply the resulting theory to these two cases, re-deriving existing results. We also apply our approach to a new setting, i.e. open Petri nets, with the usual result of reducing input transitions. Our theory generalizes Leifer and Milner reactive systems by adding observations.