  We present a relation-algebraic model of Condorcet voting and, based on it,
relation-algebraic solutions of the constructive control problem via the
removal of voters.
  We consider two winning conditions, viz. to be a Condorcet winner and to be
in the (Gilles resp. upward) uncovered set. For the first condition the control
problem is known to be NP-hard; for the second condition the NP-hardness of the
control problem is shown in the paper. All relation-algebraic specifications we
will develop in the paper immediately can be translated into the programming
language of the BDD-based computer system RelView. Our approach is very
flexible and especially appropriate for prototyping and experimentation, and as
such very instructive for educational purposes. It can easily be applied to
other voting rules and control problems.
