proposition: Lemma map_agree_Some_l {A} (m1 m2 : M A) i x: map_agree m1 m2 → m1 !! i = Some x → m2 !! i = Some x ∨ m2 !! i = None.
proof: Proof. rewrite map_agree_spec. destruct (m2 !! i) eqn: ?; naive_solver. Qed.
imports: Coq(Permutation) stdpp(options)