  void print_plane(std::ostream& out, const CGAL::Plane_3<R>& p) {
    print_plane_impl(out, Nef_3_internal::get_plane(p), typename Fraction_traits<typename R::FT>::Decompose() );
  }
  void print_plane(std::ostream& out, const CGAL::Plane_3<R>& p) {
    print_plane_impl(out, Nef_3_internal::get_plane(p), typename Fraction_traits<typename R::FT>::Decompose() );
  }