Section Intuitionistic_Tarski_to_Tarski.
Context `{BTn:intuitionistic_Tarski_neutral_dimensionless}.
Definition BetT A B C := IBet A B C \/ A=B \/ B=C.
(* Lemma 4.1 page 22 *)

Lemma five_segment:
forall A A' B B' C C' D D' : ITpoint,
ICong A B A' B' ->
ICong B C B' C' ->
ICong A D A' D' ->
ICong B D B' D' ->
BetT A B C -> BetT A' B' C' -> A <> B -> ICong C D C' D'.