Abadieʹs Constraint Qualification, Hoffmanʹs Error Bounds, and Hausdorff Strong Unicity Original Research Article

The main goal of this paper is to show the connection between optimization and best approximation when studying vector-valued functions defined on a finite set. For example, Hausdorff strong unicity for best approximation is shown to be equivalent to Abadieʹs constraint qualification for the associated convex quadratic feasibility problem.