
template<typename Kernel > 
Comparison_result  CGAL::compare_slope (const CGAL::Line_2< Kernel > &l1, const CGAL::Line_2< Kernel > &l2) 
 compares the slopes of the lines l1 and l2


template<typename Kernel > 
Comparison_result  CGAL::compare_slope (const CGAL::Segment_2< Kernel > &s1, const CGAL::Segment_2< Kernel > &s2) 
 compares the slopes of the segments s1 and s2 , where the slope is the variation of the y coordinate from the left to the right endpoint of the segments.


template<typename Kernel > 
Comparison_result  CGAL::compare_slope (const CGAL::Point_3< Kernel > &p, const CGAL::Point_3< Kernel > &q, const CGAL::Point_3< Kernel > &r, const CGAL::Point_3< Kernel > &s) 
 compares the slopes of the segments (p,q) and (r,s) , where the slope is the variation of the z coordinate from the first to the second point of the segment divided by the length of the segment.

