Require Export GeoCoq.Elements.OriginalProofs.lemma_lessthancongruence.
Require Export GeoCoq.Elements.OriginalProofs.lemma_3_6b.
Require Export GeoCoq.Elements.OriginalProofs.lemma_partnotequalwhole.
Section Euclid.
Context `{Ax:euclidean_neutral_ruler_compass}.

(* Specifications: *)
Lemma lemma_trichotomy2 :
forall A B C D,
Lt A B C D ->
~ Lt C D A B.