Petri nets, is such a transition allowed?

Question

Mathematics

Welcome all! In the screenshot, he gave an example of a Petri net, when there are two chips in the first position. Do I understand correctly that the transition t3 is allowed, and after two transitions we will get 0 from 2? The question is most likely stupid, but in the evening I decided to play it safe with the issue of the disappearance of chips)

Answer 1

Transitions t ₁ and t ₂ are created in position by one chip. Transition t ₃ simply removes one token. Available. And after two executions of the transition t ₃ , not a single chip will remain.