proposition: Lemma cong_mid_perp_bisect : forall P Q A B, P <> Q -> A <> B -> Cong A P B P -> Midpoint Q A B -> Perp_bisect P Q A B.
proof: Proof. intros. apply cong_cop_perp_bisect; Cong; Cop. Qed.
imports: GeoCoq.Tarski_dev.Ch10_line_reflexivity_2