proposition: Lemma sub_eq s1 s2 t : (forall x, In x (vars t) -> s1 x = s2 x) -> sub s1 t = sub s2 t.
proof: Proof. intro. unfold sub. rewrite (term_int_eq I0 s1 s2 t H). refl. Qed.
imports: CoLoR(AInterpretation AContext VecUtil NatUtil LogicUtil ListUtil EqUtil)