Parallel finite automata for modeling concurrent software systems
Abstract The class of parallel finite automata (PFAs) is described that naturally expresses the interleaving parallelism inherent in Petri net notation without admitting the possibility of an infinite state space. The equivalence of this class to deterministic finite automata (DFAs) is demonstrated via an algorithm for generating an equivalent nondeterministic finite automaton (NFA) from a PFA. A composition rule is given for constructing a PFA from a regular expression with the interleaving operator. Finally, the languages generated by this class are related to known classes of Petri net languages. Though class PFA is equivalent in recognition power to class DFA, the fact that DFAs are a structural subset of PFAs makes the PFA representation preferable for many applications requiring finite automata models. As an example, we discuss the usefulness of PFA notation as a structural model for hypertex and nonlinear interactive information networks in general.