Definition BetT A B C := IBet A B C \/ A=B \/ B=C.

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'.