In: Theoretical Computer Science Vol. 153, No. 1--2, pages 245-270. 1996.
Abstract: This paper is concerned with the concepts of contact and confusion in net theory. The modeling power of contacts is investigated and related to the description of the non sequential behaviour by means of concurrent processes. In a second part of notion of confusion, primarily asymmetric confusion, is examined. It is shown that this phenomenon is inherent to any reasonable net model of a mutual exclusion module. As examples of possible consequences we briefly discuss metastability in bistable asynchronous devices, limitations for the modelling power of free-choice nets, and implications for fairness- and priority-requirements in distributed systems.