Pure strategy Nash equilibria of non-zero-sum two-person games: non-convex case

Consider the class of the non-zero-sum two-person games on the unit square. If the payoff functions are continuous and satisfy a new and weaker condition than the usual conditions of concavity, or quasiconcavity, we prove that these games possess a pure strategy Nash equilibrium. (C) 1999 Elsevier Science S.A. All rights reserved.