Diploma Thesis. Dipartimento di Scienze dell'Informazione, Università degli Studi di Milano, Italy, 1990/91. In Italian.
Abstract: The scope of the thesis is to apply the approach of Meseguer and Montanari `Petri (place transition) nets are monoids' to elementary net (EN) systems. It is shown that `EN systems are not monoids'. However, some of the ideas of the work of Meseguer and Montanari can still be applied in the case of EN systems; the development of such idesas gives rise to a new model, characterized by the definition of partial structures, whose properties are comparable with that of the model for place/transition nets. That leads to the definition of elementary net systems as bicategory (actually a 2-category).
Keywords: categorial approaches (to nets); elementary net systems (as) bicategory; (2-) category; partial structure; place/transition net.