(plural Petri nets)
- One of several mathematical representations of discrete distributed systems, a 5-tuple , where
- is a set of places.
- is a set of transitions.
- and are disjoint, i.e. no object can be both a place and a transition
- is a set of arcs known as a flow relation. The set is subject to the constraint that no arc may connect two places or two transitions, or more formally: .
- is an initial marking, where for each place , there are tokens.
- is a set of arc weights, which assigns to each arc some denoting how many tokens are consumed from a place by a transition, or alternatively, how many tokens are produced by a transition and put into each place.
Named after Carl Adam Petri (1926–2010), German mathematician and computer scientist.