Symbolic Transition Graph with Assignment

A new model for message-passing processes is proposed which generalizes the notion of symbolic transition graph as introduced in [HL95], by allowing assignments to be carried in transitions. The main advantage of this generalization is that a wider class of processes can be represented as finite state graphs. Two kinds of operational semantics, ground and symbolic, are given to such graphs. On top of them both ground and symbolic bisimulations are defined and are shown to agree with each other. An algorithm is also presented which computes bisimulation formulae for finite state symbolic transition graphs with assignments, in terms of the greatest solutions of predicate equation systems.