(** ** $ 1 + x^{\ast} x = x $ #1 + x* x = x# *)

(* Specifications: *)
Lemma matches_Star_left_s : forall s r, (Star r) ~= s = (Eps || (Star r ++ r)) ~= s.
Lemma matches_Star_left : forall r, Star r =R= Eps || (Star r ++ r).