Natural SciencesMathematicsContract TheoryMicroeconomicsOptimizationConstrained OptimizationConvex AnalysisConvex OptimizationNonlinear ProgrammingOptimal ControlOptimization TheoryExistence Of MinimizersKarush-kuhn-tucker ConditionsLagrange MultipliersMinimax TheoremSaddle Point OptimizationSaddle Point Problems