appSubst :: (Ord v, SubstVars v t a) => GSubst v t -> a :-> a
appSubst subst = substVars (substFun subst)
appSubst :: (Ord v, SubstVars v t a) => GSubst v t -> a :-> a
appSubst subst = substVars (substFun subst)
appSubst subst = substVars (substFun subst)