Waldemar Korczyniski. On a presentation of Petri nets and their morphisms. In Ewa Orlowska, Andrzej Szalas, editors, Participants Copies for Relational Methods in Logic, Algebra and Computer Science, 4th International Seminar RelMiCS, Warsaw, Poland, Septermber 14-20, 1998. pages 144-147, 1998.
Abstract is missing.