a1 Department of Mathematics University of Melbourne Parkville, Victoria 3052, Australia
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.
(Received January 25 1983)
(Revised June 18 1983)
1980 Mathematics subject classification (Amer. Math. Soc.)