You may use the group
attribute of the nodes:
digraph {
3[group=b];
node[group=a]
1 -> 2 -> end;
2 -> 3;
}
Question
digraph {
1 -> 2 -> 3;
2 -> { rank = sink; end};
}
How can I force the "end" node to be centered horizontally (in the same column as the first node)?