digraph G {
  /* splines = false; */
  node [ shape = "circle" ];
  c0
  c1
  c2
  n0
  n1
  n2

  n0 -> n1;
  n0 -> n2;
  n1 -> n2;

  c0 -> c1;
  c0 -> c2;
  c1 -> c0;
  c1 -> c2;
  c2 -> c0;
  c2 -> c1;


  n0 -> c0;
  n0 -> c2;
  n1 -> c1;
  n1 -> c0;
  n2 -> c0;
  n2 -> c2;
}