Towards a Rigorous Interpretation of ESML: Extended Systems Modeling Language

摘要

A graphics-based language known as extended systems modeling language (ESML),which is an extension of the data flow diagram notation for representing control logic in models of real-time systems, is analyzed and summarized aiming at a rigorous interpretation of ESML symbols and their combinations. Based on elementary and compact or high-level Petri nets (PN), for which a succinct introduction is given, formal foundations for ESML, in particular for its transformation schema (TS) notation, are proposed. Translation principles as well as examples of usual transformation and flow patterns are presented in TS notation and PN notation. The obtained PN models can be executed due to their formally defined token game which includes concurrency of events and values as tokens. This permits a rigorous analysis of the dynamics of real-time systems with signals, prompts, and data flows of various kinds included in a single formalism. The conclusions list general features of the approach relevant to its application and indicate further research tasks. (Copyright (c) GMD 1991.)