proposition: Lemma remove_o m x y : find y (remove x m) = if K.eq_dec x y then None else find y m.
proof: Proof. destruct (K.eq_dec x y); auto with map. Qed.
imports: Coq(Bool Equalities Orders OrdersFacts OrdersLists) Coq(Morphisms Permutation SetoidPermutation) MMaps(Utils Comparisons Interface)