proposition: Lemma suppa_right_comm : forall A B C D E F, SuppA A B C D E F -> SuppA A B C F E D.
proof: Proof. unfold SuppA. intros; spliter. split; auto. ex_and H0 A'. exists A'. split; auto. apply conga_left_comm, H1. Qed.
imports: GeoCoq.Tarski_dev.Ch10_line_reflexivity_2