proposition: Theorem ResTripletInResTriplets : forall (t : triplet) (L : list triplet), In t L -> incl (ResTriplet t) (ResTriplets L).
proof: Proof. intros t L; elim L; simpl in |- *; auto with stalmarck. intros H'; elim H'; auto with stalmarck. intros a l H' H'0; Elimc H'0; intros H'0; [ rewrite <- H'0 | idtac ]; auto with datatypes stalmarck. Qed.
imports: Stalmarck(stalmarck) Stalmarck(ltState)