PN: States and Events
In a PN model, states are associated to places and marks, and events to transitions.
- A transition t is said to be enabled if each input place Pi of t is marked with at least w(Pi,t) tokens, where w(Pi,t) is the weight of the arc between Pi and t.
- An enabled transition will fire when its associated event occurs.
- Firing the transition t, w(Pi,t) tokens will be removed from each input place Pi of t, and w(t,Po) tokens will be added to each output place Po of t.