In: 91; 3rd Workshop on Concurrency and Compositionality, 1991, Goslar, Germany / Best, E.; et al.: GMD-Studien Nr. 191; Hildesheimer Informatik-Berichte 6, pages 207-215. St. Augustin, Germany: Gesellschaft für Mathematik und Datenverarbeitung mbH --- Universität Hildesheim (Germany), Institut für Informatik, May 1991.
Abstract: The author studies elementary net (EN) systems in two levels: one EN system describing the specification of the tasks (or statements or programs), the other EN system describing the set of functional units (or processors, or operating systems) performing the tasks together with the channels connecting them. Using this approach the author proves that interleaving and concurrent semantics are not equivalent.
Keywords: modelling concurrency (by) task/flow elementary net systems; task specification; functional unit; interleaving semantics; concurrent semantics.