Transitions
Event Log
Ready. Click a transition or "Full Cycle".
Petri Net State
How It Works
This is the simplest interesting Petri net: a cyclic state machine with three places and three transitions.
- red → go → green: Light turns green
- green → slow → yellow: Light turns yellow
- yellow → stop → red: Light turns red
A single token circulates endlessly through the three places. The net is live (always has an enabled transition), bounded (each place holds at most 1 token), and deadlock-free.
This pattern — a token ring — appears in everything from traffic signals to round-robin schedulers.