The conventional Lagrangian approach to solving constrained optimizati
on problems leads to optimality conditions which are either necessary,
or sufficient? but not both unless the underlying cost and constraint
functions are also convex. We introduce a new approach based on the T
chebyshev norm. This leads to an optimality condition which is both su
fficient and necessary, without any convexity assumption. This optimal
ity condition can be used to devise a conceptually simple method for s
olving nonconvex inequality constrained optimization problems.