\begin{ccRefFunction}{lexicographically_smaller}
\ccInclude{CGAL/predicates_d.h}

\ccFunction{ bool lexicographically_smaller(const Point_d<R>& p, const
  Point_d<R>& q);}{returns \ccc{true} iff \ccc{p} is
  lexicographically smaller than \ccc{q} with respect to Cartesian
  lexicographic order of points.  \ccPrecond
  \ccc{p.dimension() == q.dimension()}.}

\end{ccRefFunction}