intros.
unfold Rim, Gim3, Gim2, Gim, imageGram in |- *; simpl in |- *.
replace (couple (f A) (word (wef u))) with (fonc (couple A (word u)));
auto.
Qed.
Hint Resolve dans_Rim.

Lemma image_Regles : Regles X V1 R1 -> Regles Xim Vim Rim.
unfold Rim, Vim, Xim, Gim3, Gim2, Gim, imageGram, Regles in |- *;
simpl in |- *.