(* Gabriel Braun November 2012 *)
Require Export GeoCoq.Tarski_dev.Ch12_parallel.
Section Quadrilateral.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

Lemma bet3_cong3_bet : forall A B C D D', A <> B -> A <> C -> A <> D -> Bet D A C -> Bet A C B -> Bet D C D' -> Cong A B C D -> Cong A D B C -> Cong D C C D'
-> Bet C B D'.