Definition T A B C : Prop := ~ (A<>B /\ B<>C /\ ~ BetH A B C).Definition ColB A B C := ~ (~ T C A B /\ ~ T A C B /\ ~ T A B C).

Lemma inner_pasch_B : forall A B C P Q, BetH A P C -> BetH B Q C -> ~ ColB A B C -> exists x, BetH P x B /\ BetH Q x A.