Require Export GeoCoq.Elements.OriginalProofs.lemma_betweennotequal.
Require Export GeoCoq.Elements.OriginalProofs.lemma_congruencesymmetric.
Section Euclid.
Context `{Ax:euclidean_neutral}.

Lemma lemma_extensionunique :
forall A B E F,
BetS A B E -> BetS A B F -> Cong B E B F ->
eq E F.