proposition: Lemma map_fold_empty {A B} (f : K → A → B → B) (b : B) : map_fold f b ∅ = b.
proof: Proof. apply (map_fold_foldr _ []); [solve_proper|..]. - intros j1 j2 z1 z2 y. by rewrite !lookup_empty. - by rewrite map_to_list_empty. Qed.
imports: Coq(Permutation) stdpp(options)