In: Theoretical Computer Science, Vol. 170, No. 1--2, pages 277-296. December 1996.
Abstract: The concatenable processes of a Petri net N can be characterized abstractly as the arrows of a symmetric monoidal category P(N). However, this is only a partial axiomatization, since it is based on a concrete, ad hoc chosen, category of symmetries Sym(N).
In this paper we give a completely abstract characterization of the category of concatenable processes of N, thus yielding an axiomatic theory of the noninterleaving behaviour of Petri nets.