Require Export GeoCoq.Elements.OriginalProofs.proposition_28B.
Require Export GeoCoq.Elements.OriginalProofs.lemma_collinearparallel.
Require Export GeoCoq.Elements.OriginalProofs.lemma_parallelsymmetric.
Require Export GeoCoq.Elements.OriginalProofs.lemma_NCdistinct.
Section Euclid.
Context `{Ax:euclidean_neutral_ruler_compass}.

(* Specifications: *)
Lemma proposition_28C :
forall B D G H,
RT B G H G H D -> OS B D G H ->
Par G B H D.