In: Proceedings of the Seventeenth Annual ACM Computer Science Conference, 1989, Louisville, KY, USA, pages 1-414 pp.. New York, NY, USA: ACM, 1989.
Abstract: A new class of `concurrent automata' is constructed. These automata are extensions of pushdown automata and Petri nets. They lie properly between ordinary Petri nets and Turing machines. In the September 1977 issue of Computing survey James Peterson states that `Any significant extension of the Petri net model tends to be equivalent to a Turing machine'. This paper settled his conjecture negatively.