I have the following list of rules:
and I want to plot a tree graph:
The thing is, I would like to have the arrows only on certain lines, such as the second one,
2->3. To this end, I shall write the rules as
and generate the tree by
TreePlot[L[],...]. My question is: how can I get the arrows only at
True positions, as in the example above?
I thought I could use directed edges and undirected edges, that is,
but i get the message
TreePlot::grph:L is not a valid graph.
How can I make it work?