proposition: Lemma lea121345 : forall A B C D E, A<>B -> C<>D -> D<>E -> LeA A B A C D E.
proof: Proof. intros A B C D E HAB HCD HDE. apply l11_31_1; try (apply out_trivial); auto. Qed.
imports: GeoCoq.Tarski_dev.Ch10_line_reflexivity_2