Research Seminar - August 15, 2003

Modelling with Simultaneity in Process Algebra

Abstract:

Process algebras are mathematical formalisms for modelling concurrent systems. In most process algebras concurrency is modelled in terms of non-deterministic interleaving and there is no mechanism for describing simultaneity. In several classes of concurrent systems, however, simultanity characterises both the behaviour of the system and the properties that the system is required to meet. For instance, the simultaneous occurrence of signals in different points of the circuit is a characteristic of the behaviour of any hardware system, and the degree of effective parallelism is a property that gives a possible measure of the performance of any concurrent system.

The Circal process algebra has the distinctive feature of allowing the simultaneous occurrence of distinct actions. The seminar will illustrate how this distinctive feature eases the modelling process and allows the verification of a wider class of system properties and the development of strategies to track errors back to the components that originated them.