“…If X is a polytope, then the auxiliary optimization problem AP(q, A, 8 ( * ) ) takes the form of minimizing a concave function over a polytope, for which algorithms do exist (e.g. Glover and Klingman, 1973;Falk and Hoffman, 1976;Carrillo, 1977). This is still a hard problem, but somewhat more satisfying than trying to find global optima for problems which have neither convex nor concave auxiliary optimization functions.…”