proposition: Lemma Equiv_Equivb : compat_cmp -> forall m m', Equiv eq_elt m m' <-> Equivb cmp m m'.
proof: Proof. unfold Equivb, Equiv, Cmp; intuition. red in H; rewrite H; eauto. red in H; rewrite <-H; eauto. Qed.
imports: Coq(Bool Equalities Orders OrdersFacts OrdersLists) Coq(Morphisms Permutation SetoidPermutation) MMaps(Utils Comparisons Interface)