Copositive-plus Lemke algorithm solves polymatrix games

A problem in visual labeling and artificial neural networks, equivalent to finding Nash equilibria for polymatrix n-person games, may be solved by the copositive-plus Lemke algorithm. Analysis suggests efficiency improves Howson's recursive method by O(n^-^1) and is same order as Eaves' L"2-formulation. Method extends to any dynamical system p' = Rp + c, Ap @? q, p >= 0.