\begin{ccRefFunction}{compare_z}
\ccInclude{CGAL/predicates_on_points_3.h}

\ccFunction{Comparison_result compare_z(const Point_3<R> &p,
                            	        const Point_3<R> &q);}
        {compares the $z$-coordinates of $p$ and $q$.}

\end{ccRefFunction}