proposition: Lemma rc_context_closed : weak_context_closed R E -> context_closed E.
proof: Proof. intro. unfold context_closed. intros. unfold clos_refl, union in H0. decomp H0. subst t2. unfold clos_refl, union. auto. apply H. hyp. Qed.
imports: CoLoR(SN ASubstitution ATerm RelUtil AContext LogicUtil VecUtil NaryFunction) Coq(List)