2.23-tree.dot

#!/usr/bin/env dot
#!/usr/bin/env dot
digraph G {
  edge [dir="none"]
  node [shape="plaintext", fontname="monospace"]
  1234 [label="(1 (2 (3 4)))"]
  234 [label="(2 (3 4))"]
  34 [label="(3 4)"]
  1
  2
  3
  4
  1234 -> 1
  1234 -> 234
  234 -> 2
  234 -> 34
  34 -> 3
  34 -> 4
}