// Author: schuessf@informatik.uni-freiburg.de
// Date: 2023-05-10

PetriNet net = (
  alphabet = {a b c d},
  places = {p0 p1 p2},
  transitions = {
    ({p0} a {p1}) 
    ({p0} b {p1}) 
    ({p1} c {p2}) 
    ({p2} d {p1}) 
  },
  initialMarking = {p0},
  acceptingPlaces = {p2}
);

assert(!buchiIsEmpty(net));