DataGuides
Constructing the strong DataGuide G:
Nodes(G)={{root}}
Edges(G)=Æ
while changes do
   choose s in Nodes(G), a in Labels
   add s’={y|x in s, (x -a->y) in Edges(DB)} to Nodes(G)
   add (x -a->y) to Edges(G)
Use hash table for Nodes(G)
This is precisely the powerset automaton
construction.