diff --git a/Cartesian_kernel/include/CGAL/Cartesian/function_objects.h b/Cartesian_kernel/include/CGAL/Cartesian/function_objects.h
index 8bb51d1b262..943cc686804 100644
--- a/Cartesian_kernel/include/CGAL/Cartesian/function_objects.h
+++ b/Cartesian_kernel/include/CGAL/Cartesian/function_objects.h
@@ -533,7 +533,7 @@ namespace CartesianKernelFunctors {
     typedef typename K::Line_2    Line_2;
     typedef typename K::Equal_2   Equal_2;
     typedef typename K::Less_signed_distance_to_line_2 Less_signed_distance_to_line_2;
-    
+
   public:
     typedef typename K::Comparison_result     result_type;
 
diff --git a/Distance_2/include/CGAL/squared_distance_2_1.h b/Distance_2/include/CGAL/squared_distance_2_1.h
index 3b4f818d90f..f9b62838e91 100644
--- a/Distance_2/include/CGAL/squared_distance_2_1.h
+++ b/Distance_2/include/CGAL/squared_distance_2_1.h
@@ -199,7 +199,7 @@ namespace internal {
       return internal::squared_distance(seg1.source(), seg2, k);
     if (seg2.source() == seg2.target())
       return internal::squared_distance(seg2.source(), seg1, k);
-    
+
     Orientation o1s = orientation(seg2.source(), seg2.target(), seg1.source());
     Orientation o1e = orientation(seg2.source(), seg2.target(), seg1.target());
     if (o1s == RIGHT_TURN) {
@@ -231,7 +231,7 @@ namespace internal {
     if (crossing1) {
       if (crossing2)
         return (FT)0;
-      
+
       c2s = CGAL::abs(wcross(seg1.source(), seg1.target(), seg2.source(), k));
       c2e = CGAL::abs(wcross(seg1.source(), seg1.target(), seg2.target(), k));
       Comparison_result dm = compare(c2s,c2e);
@@ -269,11 +269,11 @@ namespace internal {
         min1 = (dm == SMALLER) ?
                  internal::squared_distance(seg1.source(), seg2, k):
                  internal::squared_distance(seg1.target(), seg2, k);
-        
+
         c2s = CGAL::abs(wcross(seg1.source(), seg1.target(), seg2.source(), k));
         c2e = CGAL::abs(wcross(seg1.source(), seg1.target(), seg2.target(), k));
         dm = compare(c2s,c2e);
-        
+
         if (dm == EQUAL)  // should not happen.
           return internal::squared_distance_parallel(seg1, seg2, k);
         min2 = (dm == SMALLER) ?
@@ -378,7 +378,7 @@ namespace internal {
     }
   }
 
-  
+
   template <class K>
   inline typename K::RT
   _distance_measure_sub(const typename K::RT &startwcross,
diff --git a/Homogeneous_kernel/include/CGAL/Homogeneous/function_objects.h b/Homogeneous_kernel/include/CGAL/Homogeneous/function_objects.h
index b5e16c06938..97e7a68d225 100644
--- a/Homogeneous_kernel/include/CGAL/Homogeneous/function_objects.h
+++ b/Homogeneous_kernel/include/CGAL/Homogeneous/function_objects.h
@@ -767,7 +767,7 @@ namespace HomogeneousKernelFunctors {
     typedef typename K::Point_2   Point_2;
     typedef typename K::Line_2    Line_2;
     typedef typename K::Less_signed_distance_to_line_2 Less_signed_distance_to_line_2;
-    
+
   public:
     typedef Comparison_result   result_type;
 
@@ -796,7 +796,7 @@ namespace HomogeneousKernelFunctors {
 
       return compare(scaled_dist_r_minus_scaled_dist_s, 0);
     }
-    
+
     result_type
     operator()(const Line_2& l, const Point_2& p, const Point_2& q) const
     {
diff --git a/Kernel_23/doc/Kernel_23/Concepts/FunctionObjectConcepts.h b/Kernel_23/doc/Kernel_23/Concepts/FunctionObjectConcepts.h
index 6d1e13b86d3..44e13cfbbe4 100644
--- a/Kernel_23/doc/Kernel_23/Concepts/FunctionObjectConcepts.h
+++ b/Kernel_23/doc/Kernel_23/Concepts/FunctionObjectConcepts.h
@@ -978,7 +978,7 @@ public:
 
 
 
-  
+
 /*!
   \ingroup PkgKernel23ConceptsFunctionObjects
   \cgalConcept
@@ -993,23 +993,23 @@ public:
   /// @{
 
   /*!
-    compares the signed distance of `r` and `s` to the directed line through `p` and `q`. 
-  */ 
+    compares the signed distance of `r` and `s` to the directed line through `p` and `q`.
+  */
   Comparison_result operator()(const Kernel::Point_2& p,
                                const Kernel::Point_2& q,
                                const Kernel::Point_2& r,
                                const Kernel::Point_2& s);
-  
+
   /*!
-    compares the signed distance of `r` and `s` to the directed line `l`. 
-  */ 
+    compares the signed distance of `r` and `s` to the directed line `l`.
+  */
   Comparison_result operator()(const Kernel::Line_2& l,
                                const Kernel::Point_2& r,
                                const Kernel::Point_2& s);
   /// @}
 }; /* end Kernel::CompareSignedDistanceToLine_2 */
 
-  
+
 /*!
   \ingroup PkgKernel23ConceptsFunctionObjects
   \cgalConcept