proposition: Lemma suppa_left_comm : forall A B C D E F, SuppA A B C D E F -> SuppA C B A D E F.
proof: Proof. unfold SuppA. intros; spliter. ex_and H0 A'. apply conga_distinct in H1. spliter. split; auto. destruct (segment_construction C B C B) as [C' []]. exists C'. split; auto. apply conga_trans with C B A'; trivial. assert_diffs. apply conga_left_comm, l11_14; Between. Qed.
imports: GeoCoq.Tarski_dev.Ch10_line_reflexivity_2