90: PhD Thesis: TD-2. Pisa, Italy: Università, Dipartimento di Informatica, 1990.
Abstract: The thesis adresses the problem of compositionality in Petri net models. First a notion of composition of places for Place/Transition nets is introduced, and it is shown that yields a compositional semantics. In the case of Predicate/Transition nets a semantics for unmarked nets is introduced, based on the concept of behaviors, that are isomorphic classes of unfolding processes, and this semantics turns out to be compositional. This compositional semantics is extended also to marked nets. Finally, the thesis deals with the relations between Predicate/Transition nets and Structure Grammars; a translation of Predicate/Transition nets into Structure Grammars and vice versa is proposed.
Keywords: compositionality; compositional semantics; predicate/transition net; structure grammar.