-- | True if non-empty intersection
intersectsDVarSet :: DVarSet -> DVarSet -> Bool
intersectsDVarSet s1 s2 = not (s1 `disjointDVarSet` s2)
intersectsDVarSet :: DVarSet -> DVarSet -> Bool
intersectsDVarSet s1 s2 = not (s1 `disjointDVarSet` s2)
intersectsDVarSet s1 s2 = not (s1 `disjointDVarSet` s2)