DEMON (Design Methods Based on Nets) Report, DSI (Dipartimento di Scienze dell'Informazione, Università degli Studi di Milano, Italy), May 1991.
Abstract: Elementary net (EN) systems can be refined either refining one of ist places, or one of its transitions. Up to now it is still missing a unified approach to both refinement operations. In this paper the author moves towards this objective by introducing two completion procedures of EN systems. One is the Place (B-)Saturation process that is possible to realize through the transformation of an EN system into its Regional version. The other one is the Transition Saturation process that is possible to realize through the transformation of an EN system into its E-Completed version through the transitive closure of its transition relation. Both refinement notions contain as sub-cases many existing refinement definitions.
Keywords: morphisms (and) refinement (for) elementary net systems; completion procedure (of) elementary net system; place (B-) saturation process; transition saturation process; regional version, E-completed version, (of) elementary net systems.