-- | True if empty intersection
disjointDVarSet :: DVarSet -> DVarSet -> Bool
disjointDVarSet s1 s2 = disjointUDFM s1 s2
disjointDVarSet :: DVarSet -> DVarSet -> Bool
disjointDVarSet s1 s2 = disjointUDFM s1 s2
disjointDVarSet s1 s2 = disjointUDFM s1 s2