Section T6_2.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.
(* Lemma t2_8 : forall A B C D E : Tpoint, Bet A B C -> Bet D B E -> Cong A B D B -> Cong B C B E -> Cong A E C D. *)

Lemma out_to_bet :
forall A B C A' B' C',
Col A' B' C' ->
(Out B A C <-> Out B' A' C') ->
Bet A B C ->
Bet A' B' C'.