proposition: Lemma agree_insert: forall A (e1 e2 : env A) k, agree e1 e2 k -> forall x o, x <= k -> agree (raw_insert x o e1) (raw_insert x o e2) (1 + k).
proof: Proof. unfold agree. do 8 intro. intros n ?. case (le_gt_dec x n); [ case (eq_nat_dec x n) | ]; intros; do 2 lookup_insert; eauto with omega. Qed.
imports: List Dblib(DblibTactics DeBruijn)