digraph abbildung3 {
{
1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20 [shape=circle]
}
2 -> {1,11} [dir=none];
6 -> {1,11} [dir=none];
11 -> {7,16} [dir=none];
7 -> {16,1} [dir=none];
3 -> {1,17} [dir=none];
4 -> {3,9,5,8,10} [dir=none];
14 -> {10,9,8,13} [dir=none];
13 -> {19,12,18,20} [dir=none];
15 -> {19,20,18,12} [dir=none];
1 -> {11} [dir=none, color=red, label="?" fontcolor=red];
7 -> {17} [dir=none, color=red, label="?" fontcolor=red];
4 -> {14} [dir=none, color=red, label="?" fontcolor=red];
13 -> {15} [dir=none, color=red, label="?" fontcolor=red];
}