Let O, A, B, C be any four points not necessarily in one plane. Let H and K divide OA and BC proportionally, while M and N divide OB and AC proportionally. Then we shall prove that HK and MN meet at T such that OA, MN, BC are proportionally divided at H, T, K, while OB, HK, AC are proportionally divided at M, T, N, the geometrical relations being conveniently, and diagrammatically, expressed thus.