Vladivostoc, USSR: Institute for Automation and Control Processes, 1989.
Abstract: This paper discusses a formal model that is intended to support a modular approach to the design and verification of concurrent systems. A new notion of entity is introduced which is defined as Petri net together with a set of labellings, with each labelling treated as an access point designed for communication with other entities or for observation of the behaviour of an entity itself. Operations on entities, such as parallel composition, abstraction, encapsulation and autocomposition, are defined.