The best chase around.......!

See it in motion:

This cat and mouse each contain a Petri net, which can be seen in operation following these instructions:

Step 1: Click on either cat or mouse (buttons below) to open Petri net window

Step 2: Click the mouse on a place (a circle), a blue token should appear in that place

Step 3: Once a token has appeared, click on the transition (thin white button) pointed to by the place containing the token. If that transition has more than one arc pointing to it, then you will need to add more tokens

Step 4: The token should move, click on any transitions which are highlighted in red, and watch the progress as the cat or mouse thinks