  We extend the notion of some energy-type expressions based on two sets,
developed in the abstract potential theory. We also give the discretized
version of the quantities defined, similar to Chebyshev constant. This
extension allows to apply the potential-theoretic results to infinite quadratic
programming problems. Together with a cutting plane algorithm, the
Chebyshev-constant method ensures that under certain conditions, the infinite
problem can be reduced to semi-infinite or to finite problems.
