Require Export GeoCoq.Elements.OriginalProofs.proposition_20.
Require Export GeoCoq.Elements.OriginalProofs.lemma_TGflip.
Require Export GeoCoq.Elements.OriginalProofs.lemma_TGsymmetric.
Require Export GeoCoq.Elements.OriginalProofs.proposition_22.
Require Export GeoCoq.Elements.OriginalProofs.lemma_10_12.
Section Euclid.
Context `{Ax:euclidean_neutral_ruler_compass}.

Lemma lemma_Euclid4 :
forall A B C a b c,
Per A B C -> Per a b c ->
CongA A B C a b c.