Require Export GeoCoq.Elements.OriginalProofs.lemma_layoff.
Require Export GeoCoq.Elements.OriginalProofs.lemma_ray4.
Require Export GeoCoq.Elements.OriginalProofs.lemma_layoffunique.
Section Euclid.
Context `{Ax:euclidean_neutral_ruler_compass}.

(* Specifications: *)
Lemma lemma_lessthantransitive :
forall A B C D E F,
Lt A B C D -> Lt C D E F ->
Lt A B E F.