Require Export GeoCoq.Elements.OriginalProofs.lemma_8_2.
Require Export GeoCoq.Elements.OriginalProofs.lemma_8_3.
Section Euclid.
Context `{Ax1:euclidean_neutral_ruler_compass}.

(* Specifications: *)
Lemma lemma_collinearright :
forall A B C D,
Per A B D -> Col A B C -> neq C B ->
Per C B D.