digraph Memory {
  rankdir=RL;
  node [shape=box];
  M [label="Prior x memory"];
  L [label="Load p.x"];
  S [label="Store p.x"];
  L -> M [color=blue]; S -> M [color=blue];
  S -> L [style=dashed,label="execute load first"];
  Y [label="Store p.y: independent"];
}