̈ find x ∈ R s. t. x i ≥ 0, Fi(x)≥ 0, x iFi(x) = 0, for i = 1, · · · ,n, where F(x) : R → R is assumed to be continuously differentiable. There have been extensive studies for complementarity problems, see for example [5] and a recent review paper [7]. The NCP was introduced by Cottle [4] in his Ph.D. thesis in 1964. At the beginning, it was recognized that the NCP is a special case of a variati...