Invex functions and duality
B. D. Craven, B. M. Glover · Journal of the Australian Mathematical Society Series A Pure Mathematics and Statistics · 1985
Abstract For both differentiable and nondifferentiable functions defined in abstract spaces we characterize the generalized convex property, here called cone-invexity, in terms of Lagrange multipliers. Several classes of such functions are given. In addition an extended Kuhn-Tucker type optimality condition and a duality result are obtained for quasidifferentiable programming problems.