unfold Derivestar in |- *.
intros u v Hyp.
unfold Derivestar, Rstar in Hyp.
pattern u, v in |- *.
apply Hyp.
auto. (*Intros; Apply Rstar_reflexive. *)
intros a b c DeriveR1 Rst.
apply Rstar_R with (y := wef b); auto.
Qed.
Hint Resolve Derivestar_image.

Lemma Reconnait_imageGram :
forall w : Word, LG X V1 R1 S1 w -> LG Xim Vim Rim Sim (wef w).