{ Petri net generated by APT for net exercise 7.2 net } PLACE s1, s2, s3, s4, s5, s6, s7; MARKING s1 : 1, s6 : 1, s7 : 1; TRANSITION t1 CONSUME s5 : 1; PRODUCE s1 : 1; TRANSITION t2 CONSUME s1 : 1, s2 : 1; PRODUCE s6 : 1, s5 : 1; TRANSITION t3 CONSUME s3 : 1, s4 : 1; PRODUCE s2 : 1; TRANSITION t4 CONSUME s7 : 1; PRODUCE s3 : 1; TRANSITION t5 CONSUME s6 : 1; PRODUCE s7 : 1, s4 : 1;