Persistent Transition Systems and Choice-Free Petri Nets

In a persistent labelled transition system, concurrency and conflict are not quite as intricately interrelated as might be the case in general. A large class of persistent transition systems allows a decomposition into small cycles with disjoint label sets. For those generated by a Petri net, this corresponds to a covering by mutually disjoint minimal T-invariants. A closely related Petri net class is called choice-free Petri nets. Persistent transition systems and choice-free nets are introduced in this chapter. In later chapters, it will be argued that Petri net synthesis can be performed fairly efficiently if attention is restricted to these classes.