diff --git a/Circular_kernel_3/include/CGAL/Circular_kernel_3/function_objects_polynomial_sphere.h b/Circular_kernel_3/include/CGAL/Circular_kernel_3/function_objects_polynomial_sphere.h
index 33bcee9fa25..7446ad2f99d 100644
--- a/Circular_kernel_3/include/CGAL/Circular_kernel_3/function_objects_polynomial_sphere.h
+++ b/Circular_kernel_3/include/CGAL/Circular_kernel_3/function_objects_polynomial_sphere.h
@@ -411,25 +411,18 @@ template < class SK > \
 
   template < class SK >
   class Construct_sphere_3
-#ifndef  CGAL_CFG_MATCHING_BUG_6
- : public  SK::Linear_kernel::Construct_sphere_3
-#endif
   {
-	  typedef typename SK::Circular_arc_3 Circular_arc_3;
-	
-  public:
-    
-		typedef typename SK::Linear_kernel::Construct_sphere_3::result_type result_type; 
-#ifndef CGAL_CFG_MATCHING_BUG_6
-    using SK::Linear_kernel::Construct_sphere_3::operator();
-#else 
+    typedef typename SK::Circular_arc_3 Circular_arc_3;
     typedef typename SK::Linear_kernel LK;
     typedef typename LK::Point_3 Point_3;
     typedef typename LK::Circle_3 Circle_3;
     typedef typename LK::Sphere_3 Sphere_3;
     typedef typename LK::Construct_sphere_3 LK_Construct_sphere_3;
     typedef typename LK::FT FT;
-
+	
+  public:
+    
+    typedef typename SK::Linear_kernel::Construct_sphere_3::result_type result_type; 
 
     result_type
     operator()( Return_base_tag tag, const Point_3& center, const FT& squared_radius,
@@ -492,11 +485,6 @@ template < class SK > \
     operator() (const Circle_3 & c) const
     { return LK_Construct_sphere_3()(c); }
 
-
-
-
-#endif
-
     result_type
     operator() ( const typename SK::Polynomial_for_spheres_2_3 &eq )
     { return SphericalFunctors::construct_sphere_3<SK>(eq); }
@@ -508,19 +496,8 @@ template < class SK > \
 
   template < class SK >
   class Construct_plane_3
-#ifndef CGAL_CFG_MATCHING_BUG_6
- : public  SK::Linear_kernel::Construct_plane_3
-#endif
   {
-	  typedef typename SK::Circular_arc_3 Circular_arc_3;
-	
-  public:
-    
-		typedef typename SK::Linear_kernel::Construct_plane_3::result_type result_type;
-
-#ifndef CGAL_CFG_MATCHING_BUG_6    
-    using SK::Linear_kernel::Construct_plane_3::operator();
-#else 
+    typedef typename SK::Circular_arc_3 Circular_arc_3;
     typedef typename SK::Linear_kernel LK;
     typedef typename LK::Construct_plane_3 LK_Construct_plane_3;
     typedef typename LK::RT           RT;
@@ -533,6 +510,10 @@ template < class SK > \
     typedef typename LK::Plane_3      Plane_3;
     typedef typename LK::Circle_3     Circle_3;
 
+  public:
+    
+    typedef typename SK::Linear_kernel::Construct_plane_3::result_type result_type;
+
   public:
 
     result_type
@@ -599,8 +580,6 @@ template < class SK > \
     operator()(const Circle_3 & c) const
     { return this->operator()(Return_base_tag(), c); }
 
-#endif
-
     result_type
     operator() ( const typename SK::Polynomial_1_3 &eq )
     { return SphericalFunctors::construct_plane_3<SK>(eq); }
@@ -616,70 +595,61 @@ template < class SK > \
   {
     typedef typename SK::Line_arc_3                Line_arc_3;
     typedef typename SK::Line_3                    Line_3;
-
-    typedef typename SK::Linear_kernel::Construct_line_3::result_type forwarded_result_type;
-  public:
     typedef typename SK::Point_3 Point_3;
     typedef typename SK::Direction_3 Direction_3;
     typedef typename SK::Vector_3 Vector_3;
     typedef typename SK::Segment_3 Segment_3;
     typedef typename SK::Ray_3 Ray_3;
+  public:
+    typedef typename SK::Linear_kernel::Construct_line_3 LK_Construct_line_3;
+    typedef typename LK_Construct_line_3::result_type result_type;
     
-    template<class>
-    struct result {
-      typedef forwarded_result_type type;
-    };
-
-    template<typename F>
-    struct result<F(Line_arc_3)> {
-      typdef const forwarded_result_type& type;
-    };
-
-    forwarded_result_type
+    result_type
     operator()(Return_base_tag, const Point_3& p, const Point_3& q) const
     { return LK_Construct_line_3()(p, Vector_3(p, q)); }
 
-    forwarded_result_type
+    result_type
     operator()(Return_base_tag, const Point_3& p, const Direction_3& d) const
     { return operator()(Return_base_tag(), p, Vector_3(d.dx(), d.dy(), d.dz())); }
 
-    forwarded_result_type
+    result_type
     operator()(Return_base_tag, const Point_3& p, const Vector_3& v) const
     { return LK_Construct_line_3()(p, v); }
 
-    forwarded_result_type
+    result_type
     operator()(Return_base_tag, const Segment_3& s) const
     { return LK_Construct_line_3()(s.source(), Vector_3(s.source(), s.target())); }
 
-    forwarded_result_type
+    result_type
     operator()(Return_base_tag, const Ray_3& r) const
     { return LK_Construct_line_3()(r.source(), Vector_3(r.source(), r.second_point())); }
 
 
-    forwarded_result_type
+    result_type
     operator()(const Point_3& p, const Point_3& q) const
     { return this->operator()(Return_base_tag(), p, q); }
 
-    forwarded_result_type
+    result_type
     operator()(const Point_3& p, const Direction_3& d) const
     { return this->operator()(Return_base_tag(), p, d); }
 
-    forwarded_result_type
+    result_type
     operator()(const Point_3& p, const Vector_3& v) const
     { return this->operator()(Return_base_tag(), p, v); }
 
-    forwarded_result_type
+    result_type
     operator()(const Segment_3& s) const
     { return this->operator()(Return_base_tag(), s); }
 
-    forwarded_result_type
+    result_type
     operator()(const Ray_3& r) const
     { return this->operator()(Return_base_tag(), r); }
 
-    const forwarded_result_type& operator() (const Line_arc_3 & a) const
+    const result_type& 
+    operator() (const Line_arc_3 & a) const
     { return (a.rep().supporting_line()); }
 
-    forwarded_result_type
+    result_type
     operator() ( const typename SK::Polynomials_for_line_3 &eq )
     { return SphericalFunctors::construct_line_3<SK>(eq); }
 
diff --git a/Filtered_kernel/include/CGAL/Lazy_kernel.h b/Filtered_kernel/include/CGAL/Lazy_kernel.h
index 8bc423075ba..5eac3ca8b4f 100644
--- a/Filtered_kernel/include/CGAL/Lazy_kernel.h
+++ b/Filtered_kernel/include/CGAL/Lazy_kernel.h
@@ -31,6 +31,7 @@
 #include <CGAL/Filtered_kernel/Cartesian_coordinate_iterator_2.h>
 #include <CGAL/Filtered_kernel/Cartesian_coordinate_iterator_3.h>
 #include <CGAL/Lazy.h>
+
 #include <boost/mpl/if.hpp>
 #include <boost/mpl/eval_if.hpp>
 #include <boost/mpl/not.hpp>
@@ -47,9 +48,6 @@ struct Delayed_void_result {
   typedef typename T::template result<void>::type type;
 };
 
-template<typename T>
-struct foobar;
-
 // goes through the standard process of selecting the right
 // Lazy_something after the kind of the return type has been
 // determined
@@ -76,6 +74,7 @@ class Lazy_kernel_generic_base
     // TODO : Static_filters_base too ?  Check performance
 {
 public:
+
   typedef AK_   Approximate_kernel;
   typedef EK_   Exact_kernel;
   typedef E2A_  E2A;
@@ -158,7 +157,6 @@ public:
     typedef Filtered_predicate<typename Exact_kernel::P, typename Approximate_kernel::P, C2E, C2F> P; \
     P Pf() const { return P(); }
 
-
     // We change the constructions.
 #ifdef CGAL_INTERSECT_WITH_ITERATORS_2
 #define CGAL_Kernel_cons(C, Cf) \
@@ -180,9 +178,9 @@ public:
   typedef typename boost::mpl::eval_if< boost::mpl::not_< boost::is_same< typename boost::result_of< typename Approximate_kernel::C () >::type, void > >, \
                                         internal::Standard_pick< typename boost::result_of<typename Approximate_kernel::C () >::type, Approximate_kernel, Exact_kernel, Kernel, typename Approximate_kernel::C, typename Exact_kernel::C >, \
                                         internal::Standard_pick< typename boost::mpl::eval_if< boost::is_same< typename boost::result_of< typename Approximate_kernel::C () >::type, void >, \
-                                                                                                 internal::Delayed_void_result< typename Approximate_kernel::C >, \
-                                                                                                 boost::mpl::identity<void> >::type, \
-                                                                   Approximate_kernel, Exact_kernel, Kernel, typename Approximate_kernel::C, typename Exact_kernel::C > \
+                                                                                               internal::Delayed_void_result< typename Approximate_kernel::C >, \
+                                                                                               boost::mpl::identity<void> >::type, \
+                                                                 Approximate_kernel, Exact_kernel, Kernel, typename Approximate_kernel::C, typename Exact_kernel::C > \
                                         >::type C;                      \
   C Cf() const { return C(); }