digraph Memory {
  rankdir=RL;
  node [shape=box];
  M0 [label="Initial memory"];
  X [label="Store p.x = 3"];
  Y [label="Store p.y = arg"];
  L [label="Load p.x"];
  L -> Y -> X -> M0 [color=blue];
  Return -> Y [color=blue]; Return -> L;
}