Section Euclid.
Context `{Ax:area}.

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.