delBindersFV :: [Var] -> DVarSet -> DVarSet
delBindersFV bs fvs = foldr delBinderFV fvs bs
delBindersFV :: [Var] -> DVarSet -> DVarSet
delBindersFV bs fvs = foldr delBinderFV fvs bs
delBindersFV bs fvs = foldr delBinderFV fvs bs