Rapport LRI--571, pages 1-13 pp.. Univ. de Paris-Sud, Centre d'Orsay, France, Laboratoire de Recherche en Informatique, 1990.
Abstract: When describing the behaviour of P/T systems by arbitrary interleaving of transition occurrences, any sequentialisation of independent actions is defined to be an occurrence sequence of the system. The so described system behaviours are sequential languages. For this semantics an extension of the monadic second order logic L1 of Büchi, called L, is defined. In this paper, the author expresses the concurrent behaviour of a P/T system by its partial words (obtained from the processes by making abstraction of the places). It is proven that for each P/T system its partial word language is definable by existential L-sentences.
Keywords: place/transition system; concurrent behaviour (and) logic; sequential language; monadic second order logic; partial word language.