proposition: Theorem eq_remove : forall A x (E F : gen_env A), ok E -> ok F -> E ≍ F -> E ∖ {x} ≍ F ∖ {x}.
proof: Proof. intros A x E F Hok1 Hok2 Heq. unfold eq in *. destruct Heq. split; apply all_binds_remove_compat; auto. Qed.
imports: Utf8 Equalities CoreGenericEnv