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

Lemma l6_11_existence : forall A B C R,
R<>A -> B<>C -> exists X, Out A X R /\ Cong A X B C.