Petri net

A Petri net (also known as a place/transition net or P/T net) is one of several mathematical representations of discrete distributed systems. As a modeling language, it graphically depicts the structure of a distributed system as a directed bipartite graph with annotations. As such, a Petri net has place nodes, transition nodes, and directed arcs connecting places with transitions. Petri nets were invented in 1962 by Carl Adam Petri.
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<parallel, simulation> A directed, bipartite graph in which nodes are either "places" (represented by circles) or "transitions" (represented by rectangles), invented by Carl Adam Petri. A Petri net is marked by placing "tokens" on places. When all the places