digraph Memory {
  rankdir=RL;
  node [shape=box];
  P [label="MemPhi(x)"];
  B [label="BulkMemPhi(All except x)"];
  P -> Left [label="slice x",color=blue]; P -> Right [label="slice x",color=blue];
  B -> Left; B -> Right;
  P -> Region [style=dashed]; B -> Region [style=dashed];
  MemMerge -> P [label="x",color=blue]; MemMerge -> B [label="default"];
}