proposition: Lemma lemma_ray5 : forall A B C, Out A B C -> Out A C B.
proof: Proof. intros. assert ((BetS A C B \/ eq B C \/ BetS A B C)) by (conclude lemma_ray1). assert (neq A C) by (conclude lemma_raystrict). assert (Out A C B) by (conclude lemma_ray4). close. Qed.
imports: GeoCoq.Elements.OriginalProofs.lemma_ray1 GeoCoq.Elements.OriginalProofs.lemma_raystrict GeoCoq.Elements.OriginalProofs.lemma_ray4