Definition Supplementary (alpha beta : AS) :=
exists A  : Point,  exists B  : Point,  exists C : Point,  exists D : Point, 
	A <> C /\ Between B A D /\ Angle B A C = alpha /\ Angle C A D = beta.

Lemma SupplementaryRec : forall A B C D : Point, Clockwise B A C -> Clockwise C A D -> Supplementary (Angle B A C) (Angle C A D) -> Between B A D.