Require Export GeoCoq.Elements.OriginalProofs.proposition_23C.
Section Euclid.
Context `{Ax:euclidean_neutral_ruler_compass}.

Lemma lemma_angletrichotomy2 :
forall A B C D E F,
nCol A B C -> nCol D E F -> ~ CongA A B C D E F -> ~ LtA D E F A B C ->
LtA A B C D E F.