The main result proved in this paper is that the ratio of the square of a nonnegative convex function to a strictly positive concave function is convex over a convex domain. Some particular cases of ...

Mathematics of Operations Research, Vol. 20, No. 4 (Nov., 1995), pp. 818-837 (20 pages) A nonlinear extension of Farkas' lemma for systems involving the difference of sublinear functions is presented.