Section Hilbert_2D_to_Tarski_2D.
Context `{Hi:Hilbert_neutral_dimensionless}.
(** Tarski's betweenness is not strict: *)
Definition Bet A B C := BetH A B C \/ A = B \/ B = C.

Lemma colH_trivial121 : forall A B, ColH A B A.
Hint Resolve colH_trivial121 colH_trivial122 colH_trivial112 colH_trivial111 colH_permut_231 colH_permut_312 colH_permut_321
colH_permut_213 colH_permut_132 colH_permut_231 : colH.