Require Export GeoCoq.Elements.OriginalProofs.lemma_notperp.
Require Export GeoCoq.Elements.OriginalProofs.lemma_pointreflectionisometry.
Require Export GeoCoq.Elements.OriginalProofs.lemma_planeseparation.
Require Export GeoCoq.Elements.OriginalProofs.lemma_oppositesidesymmetric.
Section Euclid.
Context `{Ax:euclidean_neutral_ruler_compass}.

Lemma proposition_11B :
forall A B C P,
BetS A C B -> nCol A B P ->
exists X, Per A C X /\ TS X A B P.