Require Export GeoCoq.Elements.OriginalProofs.proposition_20.
Require Export GeoCoq.Elements.OriginalProofs.lemma_TGsymmetric.
Require Export GeoCoq.Elements.OriginalProofs.lemma_TGflip.
Require Export GeoCoq.Elements.OriginalProofs.proposition_22.
Section Euclid.
Context `{Ax:euclidean_neutral_ruler_compass}.

(* Specifications: *)
Lemma proposition_23 :
forall A B C D E,
neq A B -> nCol D C E ->
exists X Y, Out A B Y /\ CongA X A Y D C E.