In: Proceedings of the 12th International Conference on Application and Theory of Petri Nets, 1991, Gjern, Denmark, pages 455-476. June 1991.
Also as: Extended version: Technical Report i.4.26. Progretto Finalizzato Sistemi Informatici e Calcolo Parallelo. Consiglio Nazionale delle Ricerche (CNR), Italy, January 1991.
Abstract: OBJSA nets are a design specifications language for distributed systems, combining the specification language OBJ with Superposed Automata (SA) nets. The paper introduces the notions of morphism and isomorphism for OBJSA net systems and shows that any OBJSA net system can be reduced to a unique minimal model. This allows the definition of equivalence classes of OBJSA models. A net semantics for OBJSA net systems, in terms of 1-safe SA net systems, and algebraic semantics, in terms of OBJ3 objects, are given and it is proved that all the unfoldings, and, respectively, all the algebraic specifications of OBJSA models belonging to the same class are isomorphic.
Keywords: minimal model (for) OBJSA net; distributed system; specification language OBJ; 1-safe superposed automata net; OBJSA net system semantics; algebraic semantics; OBJ3 objects.