function value = f ( x, y )

%*****************************************************************************80
%
%% F evaluates the function.
%
%  Licensing:
%
%    This code is distributed under the GNU LGPL license.
%
%  Modified:
%
%    06 August 2005
%
%  Author:
%
%    John Burkardt
%
%  Parameters:
%
%    Input, real X, Y, the coordinates of a point.
%
%    Output, real VALUE, the function value at (X,Y).
%
  value = 1.0 ./ ( 1.0 - x .* y );

  return
end
