proposition: Lemma seq_max r r' b (MAX: max_elt r' b) (COD: forall x y, r x y -> y = b) : r ⨾ r' ≡ ∅₂.
proof: Proof. unfold seq; split; red; ins; desf. apply COD in H; desf; eauto. Qed.
imports: HahnBase HahnList HahnSets HahnRelationsBasic HahnEquational HahnRewrite Arith Setoid