In: Diaz, J.; et al.: Lecture Notes in Computer Science, Vol. 351; TAPSOFT'89, Vol. 1: Advanced Seminar on Foundations of Innovative Software Development, I, and Colloquium on Trees in Algebra and Programming (CAAP'89), pages 134-148. Berlin: Springer-Verlag, 1989.
Abstract: The paper begins with the question of describing the sequences of atomic actions performable by a flowchart algorithm which admits explicit nondeterminism and a forking type of parallelism. The kind of flowchart scheme is made precise in the definition of a parallel transition system; the corresponding systems of equations are the shuffle equations. The same equations were determined by a subclass of free choice Petri nets called equational Petri nets. Thus, shuffle equations, parallel transition system and equational Petri nets are equivalent descriptions of this class of algorithm scheme. The authors concentrate on the equational Petri nets.
Keywords: shuffle equation; parallel transition system; equational net; flowchart algorithm; free choice net.