intros Re_1 Re_2 inter_X_V1_V2_empty u v Der_Ru_u.
elim Der_Ru_u.
intros u0 v0 A dans_couple_Ru inmon_cons_A_v0.
apply Derive1.
cut (dans (couple A (word u0)) R1 \/ dans (couple A (word u0)) R2). (**)
intro temp; elim temp; clear temp.
auto.
intro dans_R2.
absurd (inter (union X V1) V2 empty).
red in |- *.
unfold inter in |- *.
intro temp; elim temp; clear temp.
intros incl_empty_X_V1 temp; elim temp; clear temp.
intros incl_empty_V2 imp.
apply dans_empty_imp_P with A.
apply imp.
apply inmonoid_cons_inv2 with v0; assumption.
apply Regles_inv1 with X R2 (word u0); assumption.
assumption.
(**) apply dans_union; assumption.  intros u0 v0 x Der_Ru imp inmon_cons_x_u0. apply Derive2. apply imp. apply inmonoid_cons_inv with x. assumption. Qed.   Lemma inmon_Der_imp_inmon_R1 : forall u v : Word, Regles X V1 R1 -> Derive R1 u v -> inmonoid (union X V1) u -> inmonoid (union X V1) v. intros. apply in_mon_X_Der_imp_inmon_X with R1 u; assumption. Qed.  Lemma inmon_Der_imp_inmon : forall u v : Word, isGram X V1 R1 S1 -> isGram X V2 R2 S2 -> inter V1 V2 empty -> inmonoid (union X V1) u -> Derive Ru u v -> inmonoid (union X V1) v. intros u v G_R1 G_R2 inter_V1_V2_empty inmon_X_V1_u Der_Ru_u_v. apply inmon_Der_imp_inmon_R1 with u. apply isGram4 with S1; assumption.  apply inmon_Der_imp_Der. apply isGram4 with S1; assumption.  apply isGram4 with S2; assumption.  apply inter_union. apply isGram2 with R2 S2; assumption. assumption.  assumption.  assumption.  assumption.  Qed.  Lemma Gunion_Derivestar : isGram X V1 R1 S1 -> isGram X V2 R2 S2 -> inter V1 V2 empty -> forall u v : Word, Derivestar Ru u v -> inmonoid (union X V1) u -> Derivestar R1 u v. unfold Derivestar in |- *. intros G_1 G_2 inter_V1_V2_empty u v Derivestar_Ru. pattern u, v in |- *. apply Derivestar_Ru. auto. (*Intros. Apply Rstar_reflexive.*)
intros u0 v0 w Der_Ru inmon_v0_imp_Rstar_R1_v0 inmon_u0.
(*Prolog [Rstar_R inmon_Der_imp_Der isGram4  inter_union  isGram2 inmon_Der_imp_inmon ] 6. -> raisonnable seulement sur Cray...*)
apply Rstar_R with v0.
prolog [ inmon_Der_imp_Der isGram4 inter_union isGram2 ] 5.
(*		Apply inmon_Der_imp_Der. Apply isGram4 with S1;Assumption. Apply isGram4 with S2;Assumption. Apply inter_union. Apply isGram2 with R2 S2; Assumption. Assumption. Assumption. Assumption.*)
prolog [ inmon_Der_imp_inmon ] 3.
(*		Apply inmon_v0_imp_Rstar_R1_v0. Apply inmon_Der_imp_inmon with u0;Assumption.*)
Qed.

Lemma inmon_Der_imp_Der2 :
Regles X V1 R1 ->
Regles X V2 R2 ->
inter (union X V2) V1 empty ->
forall u v : Word, Derive Ru u v -> inmonoid (union X V2) u -> Derive R2 u v.