  We obtain symmetry results for solutions of an elliptic system of equation
possessing a cooperative structure. The domain in which the problem is set may
possess "holes" or "small vacancies" (measured in terms of capacity) along
which the solution may diverge.
  The method of proof relies on the moving plane technique, which needs to be
suitably adapted here to take care of the complications arising from the
vacancies in the domain and the analytic structure of the elliptic system.
