{ Petri net generated by APT for net exercise 5.1 net }

PLACE
s1, s2, s3, s4;

MARKING
	s2	: 1;

TRANSITION t1
CONSUME
	s2	: 1;
PRODUCE
	s1	: 1;

TRANSITION t2
CONSUME
	s1	: 1;
PRODUCE
	s2	: 1,
	s3	: 1,
	s1	: 1;

TRANSITION t3
CONSUME
	s2	: 1,
	s4	: 1;
PRODUCE
	s3	: 1;

TRANSITION t4
CONSUME
	s3	: 1;
PRODUCE
	s4	: 1;