proposition: Lemma add_equal_iff : ∀ elt k (e : elt) m1 m2, P.Add k e m1 m2 <-> M.Equal (M.add k e m1) m2.
proof: Proof. split; intros; intro addr; specialize (H addr); congruence. Qed.
imports: Coq.Unicode.Utf8 Coq.FSets.FMapFacts