Proof with finish.
unfold TS.
intros.
spliter.
repeat split...
ex_and H1 T.
exists T;split...
Qed.

(* Specifications: *)
Lemma l9_3 : forall P Q A C M R B,
TS P Q A C -> Col M P Q ->
Midpoint M A C -> Col R P Q ->
Out R A B -> TS P Q B C.