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 S0 S1S2⋯ with Si= υ(Si-1). One usually assumes a finite, symbolic representation of states. The next state function υ is usually computable on this representation.