Require Export GeoCoq.Elements.OriginalProofs.lemma_squareparallelogram.
Require Export GeoCoq.Elements.OriginalProofs.lemma_samesideflip.
Require Export GeoCoq.Elements.OriginalProofs.lemma_erectedperpendicularunique.
Require Export GeoCoq.Elements.OriginalProofs.lemma_twoperpsparallel.
Require Export GeoCoq.Elements.OriginalProofs.proposition_29C.
Require Export GeoCoq.Elements.OriginalProofs.lemma_altitudeofrighttriangle.
Section Euclid.
Context `{Ax:area}.

(* Specifications: *)
Lemma proposition_47A :
forall A B C D E,
Triangle A B C -> Per B A C -> SQ B C E D -> TS D C B A ->
exists X Y, PG B X Y D /\ BetS B X C /\ PG X C E Y /\ BetS D Y E /\ BetS Y X A /\ Per D Y A.