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

(* Specifications: *)
Lemma lemma_doublereverse :
forall A B C D,
Cong A B C D ->
Cong D C B A /\ Cong B A D C.
Lemma lemma_lessthancongruence2 :
forall A B C D E F,
Lt A B C D -> Cong A B E F ->
Lt E F C D.