Kasimbeyli, R.Mammadov, M.2023-06-162023-06-1620110362-546Xhttps://doi.org/10.1016/j.na.2010.12.008https://hdl.handle.net/20.500.14365/1342In this paper we study optimality conditions for optimization problems described by a special class of directionally differentiable functions. The well-known necessary and sufficient optimality condition of nonsmooth convex optimization, given in the form of variational inequality, is generalized to the nonconvex case by using the notion of weak subdifferentials. The equivalent formulation of this condition in terms of weak subdifferentials and augmented normal cones is also presented. (C) 2010 Elsevier Ltd. All rights reserved.eninfo:eu-repo/semantics/closedAccessWeak subdifferentialDirectional derivativeNonconvex analysisOptimality conditionVariational inequalitiesAugmented normal coneRadial EpiderivativesCalculusArticle10.1016/j.na.2010.12.0082-s2.0-79951682618