Section T6_1.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.
(** out reflexivity. l6_5 *)
(** out symmetry. *)
(** out transitivity. *)

Lemma bet_out_out_bet : forall A B C A' C',
Bet A B C -> Out B A A' -> Out B C C' -> Bet A' B C'.