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 CongruentOpposedTriangles : forall A B C D I : Point, Between A I C -> Between B I D -> Distance I A = Distance I C -> Distance I B = Distance I D -> CongruentTriangles A I B C I D.