src/doc/book/dot/trpl15-04.dot

   1 digraph {
   2     node[shape=record];
   3     rankdir=LR;
   4
   5     l1[label="{<data> 5| <next>}"];
   6     l2[label="{<data> 10| <next>}"];
   7
   8     {node[shape=point height=0] invisible_start invisible_end}
   9
  10     a -> l1:n;
  11     b -> l2:n;
  12     invisible_start:n -> l1[arrowtail=none];
  13     invisible_start:s -> invisible_end:s[dir=none];
  14     l1:next:c -> l2:data;
  15     l2:next:c -> invisible_end:n[arrowhead=none];
  16 }