// dot 10-graph-src.dot -Tpng -o 10-graph.png; dot 10-graph-src.dot -Tgif -o 10-graph.gif
// dot 10-graph-src.dot -Tsvg -o 10-graph.svg

digraph Lab10Digraph {
  size="6,2";
  a [fontname="Helvetica,Arial,sans-serif"]
  b [fontname="Helvetica,Arial,sans-serif"]
  c [fontname="Helvetica,Arial,sans-serif"]
  d [fontname="Helvetica,Arial,sans-serif"]
  e [fontname="Helvetica,Arial,sans-serif"]
  f [fontname="Helvetica,Arial,sans-serif"]
  g [fontname="Helvetica,Arial,sans-serif"]
  h [fontname="Helvetica,Arial,sans-serif"]
  i [fontname="Helvetica,Arial,sans-serif"]
  j [fontname="Helvetica,Arial,sans-serif"]
  k [fontname="Helvetica,Arial,sans-serif"]
  l [fontname="Helvetica,Arial,sans-serif"]

  a->b
  a->c
  c->a
  b->d
  c->b
  
  e->f
  f->e
  g->e

  h->i
  i->j
  j->k
  k->l
  k->h
  
  {rank=same; b; d}
  {rank=same; a; c}
  {rank=same; g; e}
  {rank=same; i; j; k}
  {rank=same; h; l}
}