proposition: Lemma lemma_rectanglerotate : forall A B C D, RE A B C D -> RE B C D A.
proof: Proof. intros. assert ((Per D A B /\ Per A B C /\ Per B C D /\ Per C D A /\ CR A C B D)) by (conclude_def RE ). let Tf:=fresh in assert (Tf:exists M, (BetS A M C /\ BetS B M D)) by (conclude_def CR );destruct Tf as [M];spliter. assert (BetS C M A) by (conclude axiom_betweennesssymmetry). assert (CR B D C A) by (conclude_def CR ). assert (RE B C D A) by (conclude_def RE ). close. Qed.
imports: GeoCoq.Elements.OriginalProofs.euclidean_tactics