A rich variety of system models for sequential, deterministic systems has been suggested during recent decades, including automata, process algebras, many versions of Petri Nets, and models to describe the semantics of Programming languages. All models for sequential, deterministic systems assume a set S of states, or configurations, and a next state function υ: S → S. This yields computation sequences S 0 S 1 S 2⋯ with S i= υ (S i-1 ). One usually assumes a finite, symbolic representation of states. The next state function υ is usually computable on this representation.