  We provide formulas for projectors onto a polyhedral set, i.e. the
intersection of a finite number of halfspaces. To this aim we formulate the
problem of finding the projection as a convex optimization problem and we solve
explicitly sufficient and necessary optimality conditions. This approach has
already been successfully applied in deriving formulas for projection onto the
intersection of two halfspaces. We also discuss possible generalizations to
Banach spaces.
