Section T15.
Context `{T2D:Tarski_2D}.
Context `{TE:@Tarski_euclidean Tn TnEQD}.
(** Lemma 15.2 *)
(** Cong corresponds to length equality.*)
(** Le corresponds to length inequality.*)
(********************************************************)

Lemma ltp_to_lt : forall O E E' A B L C D M, Length O E E' A B L -> Length O E E' C D M
-> LtP O E E' L M -> Lt A B C D.