proposition: Lemma col__refl : forall A B P, Col P A B -> ReflectL P P A B.
proof: Proof. intros A B P HCol. split. exists P; split; [Midpoint|Col]. right; reflexivity. Qed.
imports: GeoCoq.Tarski_dev.Ch09_plane GeoCoq.Tarski_dev.Tactics.CoincR_for_cop