In: Freksa, C.; Jantzen, M.; Valk, R.: Lecture Notes in Computer Science, Vol. 1337: Foundations of Computer Science: Potential - Theory - Cognition, pages 307-312. Springer-Verlag, 1997.
Abstract: Protocols return often to a particular state - no matter what happens. Such a state is called a `ground state'. Each action which occurs in the ground state, starts a so called `round'. A round ends when the ground state is reached again. In distributed protocols without global control, rounds are hard to identify. Ground states may be only virtual snapshots and not necessarily observable. When partial order semantics is considered, a round can be clearly identified even in a distributed system. The paper discusses the use of rounds for structuring and verifying a system's behavior. As an example a Petri net model of the asynchronous stack is introduced.
Keywords: Petri nets, asynchronous stack, distributed protocols, ground states.