proposition: Lemma lea_distincts : forall A B C D E F, LeA A B C D E F -> A<>B /\ C<>B /\ D<>E /\ F<>E.
proof: Proof. intros A B C D E F Hlea. destruct Hlea as [X [HInAngle HConga]]. destruct HInAngle as [HDE [HEF _]]. repeat split; auto. apply (conga_diff1 A B C D E X); auto. apply (conga_diff2 A B C D E X); auto. Qed.
imports: GeoCoq.Tarski_dev.Ch10_line_reflexivity_2