petrinet4.dot

digraph G {
0 [label="right\n_\n" shape=circle]
1 [label="left\n___\n" shape=circle]
2 [label="end\n•\n" shape=circle]
3 [label="continuer" shape=box]
4 [label="joiner" shape=box]
5 [label="start\n_\n" shape=circle]
6 [label="splitter" shape=box]
7 [label="joint\n___\n" shape=circle]

0 -> 4 [label="1" ] 
1 -> 4 [label="2" ] 
3 -> 2 [label="1" ] 
4 -> 7 [label="1" ] 
5 -> 6 [label="1" ] 
6 -> 1 [label="1" ] 
6 -> 0 [label="1" ] 
7 -> 3 [label="3" ] 
}