compSubst :: (Ord v, HasVars f v, HTraversable f)
          => CxtSubst h a f v -> CxtSubst h a f v -> CxtSubst h a f v
compSubst s1 = Map.map (\ (A t) -> A (appSubst s1 t))
compSubst :: (Ord v, HasVars f v, HTraversable f)
          => CxtSubst h a f v -> CxtSubst h a f v -> CxtSubst h a f v
compSubst s1 = Map.map (\ (A t) -> A (appSubst s1 t))
compSubst s1 = Map.map (\ (A t) -> A (appSubst s1 t))