Require Export GeoCoq.Elements.OriginalProofs.lemma_collinearorder.
Section Euclid.
Context `{Ax1:euclidean_neutral}.

Lemma lemma_NCorder :
forall A B C,
nCol A B C ->
nCol B A C /\ nCol B C A /\ nCol C A B /\ nCol A C B /\ nCol C B A.