Section Angles_4.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

Lemma ang_const_o : forall a A B P, ~Col A B P -> Q_CongA a -> Q_CongA_nNull a -> Q_CongA_nFlat a -> exists C, a A B C /\ OS A B C P.