diff --git a/Filtered_kernel/include/CGAL/internal/Static_filters/Angle_3.h b/Filtered_kernel/include/CGAL/internal/Static_filters/Angle_3.h
index 5008b1bbfdf..43e0f782bf6 100644
--- a/Filtered_kernel/include/CGAL/internal/Static_filters/Angle_3.h
+++ b/Filtered_kernel/include/CGAL/internal/Static_filters/Angle_3.h
@@ -52,15 +52,14 @@ public:
 
 #ifndef CGAL_CFG_MATCHING_BUG_6
   using Base::operator();
-#else 
-
+#else // CGAL_CFG_MATCHING_BUG_6
   template <typename T1, typename T2>
   result_type
   operator()(const T1& t1, const T2& t2) const
   {
     return Base()(t1,t2);
   }
-#endif
+#endif // CGAL_CFG_MATCHING_BUG_6
 
 
   Sign sign_with_error(const double x, const double error) const {
@@ -155,13 +154,12 @@ public:
     return err;
   }
 
-}; // class Angle_3
+}; // end class Angle_3
 
-}  // namespace Static_filters_predicates
+} // end namespace Static_filters_predicates
 
-} // namespace internal
+} // end namespace internal
 
-
-} //namespace CGAL
+} // end namespace CGAL
 
 #endif  // CGAL_INTERNAL_STATIC_FILTERS_ANGLE_3_H
diff --git a/Filtered_kernel/include/CGAL/internal/Static_filters/Do_intersect_3.h b/Filtered_kernel/include/CGAL/internal/Static_filters/Do_intersect_3.h
index 5b6cd4e0316..7ac0e6136f6 100644
--- a/Filtered_kernel/include/CGAL/internal/Static_filters/Do_intersect_3.h
+++ b/Filtered_kernel/include/CGAL/internal/Static_filters/Do_intersect_3.h
@@ -56,15 +56,14 @@ public:
 
 #ifndef CGAL_CFG_MATCHING_BUG_6
   using Base::operator();
-#else 
-
+#else // CGAL_CFG_MATCHING_BUG_6
   template <typename T1, typename T2>
   result_type
   operator()(const T1& t1, const T2& t2) const
   {
     return Base()(t1,t2);
   }
-#endif
+#endif // CGAL_CFG_MATCHING_BUG_6
 
 
   Sign sign_with_error(const double x, const double error) const {
@@ -493,11 +492,11 @@ public:
 
 }; // class Do_intersect_3
 
-}  // namespace Static_filters_predicates
+} // end namespace Static_filters_predicates
 
-} // namespace internal
+} // end namespace internal
 
 
-} //namespace CGAL
+} // end namespace CGAL
 
 #endif  // CGAL_INTERNAL_STATIC_FILTERS_DO_INTERSECT_3_H
diff --git a/Filtered_kernel/include/CGAL/internal/Static_filters/Is_degenerate_3.h b/Filtered_kernel/include/CGAL/internal/Static_filters/Is_degenerate_3.h
new file mode 100644
index 00000000000..ec21318cfcd
--- /dev/null
+++ b/Filtered_kernel/include/CGAL/internal/Static_filters/Is_degenerate_3.h
@@ -0,0 +1,81 @@
+// Copyright (c) 2011 GeometryFactory (France)
+// All rights reserved.
+//
+// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public License as
+// published by the Free Software Foundation; version 2.1 of the License.
+// See the file LICENSE.LGPL distributed with CGAL.
+//
+// Licensees holding a valid commercial license may use this file in
+// accordance with the commercial license agreement provided with the software.
+//
+// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+//
+// $URL$
+// $Id$
+//
+//
+// Author(s)     : Andreas Fabri, Laurent Rineau
+
+
+#ifndef CGAL_INTERNAL_STATIC_FILTERS_IS_DEGENERATE_3_H
+#define CGAL_INTERNAL_STATIC_FILTERS_IS_DEGENERATE_3_H
+
+namespace CGAL {
+
+namespace internal {
+
+namespace Static_filters_predicates {
+
+
+template < typename K_base >
+class Is_degenerate_3
+  : public K_base::Is_degenerate_3
+{
+  typedef typename K_base::Ray_3     Ray_3;
+  typedef typename K_base::Segment_3 Segment_3;
+  typedef typename K_base::Is_degenerate_3 Base;
+  typedef typename K_base::Construct_source_3 Construct_source_3;
+  typedef typename K_base::Construct_target_3 Construct_target_3;
+  typedef typename K_base::Construct_second_point_3 Construct_second_point_3;
+  typedef typename K_base::Equal_3 Equal_3;
+public:
+
+  typedef typename Base::result_type  result_type;
+
+
+#ifndef CGAL_CFG_MATCHING_BUG_6
+  using Base::operator();
+#else // CGAL_CFG_MATCHING_BUG_6
+  template <typename T>
+  result_type
+  operator()(const T& t) const
+  {
+    return Base()(t);
+  }
+#endif // end CGAL_CFG_MATCHING_BUG_6
+
+
+  result_type 
+  operator()(const Segment_3& s) const
+  {
+    return Equal_3()(Construct_source_3()(s), Construct_target_3()(s));
+  }
+
+
+  result_type 
+  operator()(const Ray_3& r) const
+  {
+    return Equal_3()(Construct_source_3()(r), Construct_second_point_3()(r));
+  }
+
+}; // end class Is_degenerate_3
+
+} // end namespace Static_filters_predicates
+
+} // end namespace internal
+
+} // end namespace CGAL
+
+#endif  // CGAL_INTERNAL_STATIC_FILTERS_IS_DEGENERATE_3_H
diff --git a/Filtered_kernel/include/CGAL/internal/Static_filters/Static_filters.h b/Filtered_kernel/include/CGAL/internal/Static_filters/Static_filters.h
index b411e6eb0bc..1064a7ad0c0 100644
--- a/Filtered_kernel/include/CGAL/internal/Static_filters/Static_filters.h
+++ b/Filtered_kernel/include/CGAL/internal/Static_filters/Static_filters.h
@@ -37,12 +37,26 @@
 #include <CGAL/internal/Static_filters/tools.h>
 #include <CGAL/internal/Static_filters/Orientation_2.h>
 #include <CGAL/internal/Static_filters/Orientation_3.h>
+
+// for static filters added nov./dec. 2011
+#ifdef CGAL_DISABLE_RECENTLY_ADDED_STATIC_FILTERS
+#  define CGAL_NO_IS_DEGENERATE_3_STATIC_FILTERS 1
+#  define CGAL_NO_ANGLE_3_STATIC_FILTERS 1
+#  define CGAL_NO_DO_INTERSECT_3_STATIC_FILTERS 1
+#endif // CGAL_DISABLE_RECENTLY_ADDED_STATIC_FILTERS
+
+#ifndef CGAL_NO_IS_DEGENERATE_3_STATIC_FILTERS
+#  include <CGAL/internal/Static_filters/Is_degenerate_3.h>
+#endif // NOT CGAL_NO_IS_DEGENERATE_3_STATIC_FILTERS
+
 #ifndef CGAL_NO_ANGLE_3_STATIC_FILTERS
 #  include <CGAL/internal/Static_filters/Angle_3.h>
-#endif // CGAL_NO_ANGLE_3_STATIC_FILTERS
+#endif // NOT CGAL_NO_ANGLE_3_STATIC_FILTERS
+
 #ifndef CGAL_NO_DO_INTERSECT_3_STATIC_FILTERS
 #  include <CGAL/internal/Static_filters/Do_intersect_3.h>
-#endif // NOT CGAL_NO_DO_INTERSECT_3_STATIC_FILTERS
+#endif // NOT NOT CGAL_NO_DO_INTERSECT_3_STATIC_FILTERS
+
 #include <CGAL/internal/Static_filters/Compare_y_at_x_2.h>
 #include <CGAL/internal/Static_filters/Side_of_oriented_circle_2.h>
 #include <CGAL/internal/Static_filters/Side_of_oriented_sphere_3.h>
@@ -88,12 +102,14 @@ class Static_filters : public K_base {
                          has_cheap_access_to_cartesian_coordinates>         Self;
 
 public:
-
+#ifndef CGAL_NO_IS_DEGENERATE_3_STATIC_FILTERS
+  typedef Static_filters_predicates::Is_degenerate_3<K_base>                Is_degenerate_3;
+#endif // NOT CGAL_NO_IS_DEGENERATE_3_STATIC_FILTERS
   typedef Static_filters_predicates::Orientation_2<K_base>                  Orientation_2;
   typedef Static_filters_predicates::Orientation_3<K_base>                  Orientation_3;
 #ifndef CGAL_NO_ANGLE_3_STATIC_FILTERS
   typedef Static_filters_predicates::Angle_3<K_base>                        Angle_3;
-#endif // CGAL_NO_ANGLE_3_STATIC_FILTERS
+#endif // NOT CGAL_NO_ANGLE_3_STATIC_FILTERS
 #ifndef CGAL_NO_DO_INTERSECT_3_STATIC_FILTERS
   typedef Static_filters_predicates::Do_intersect_3<K_base>                 Do_intersect_3;
 #endif // NOT CGAL_NO_DO_INTERSECT_3_STATIC_FILTERS
@@ -109,6 +125,12 @@ public:
   orientation_3_object() const
   { return Orientation_3(); }
 
+#ifndef CGAL_NO_IS_DEGENERATE_3_STATIC_FILTERS
+ Is_degenerate_3
+  is_degenerate_3_object() const
+  { return Is_degenerate_3(); }
+#endif // NOT CGAL_NO_IS_DEGENERATE_3_STATIC_FILTERS
+
 #ifndef CGAL_NO_ANGLE_3_STATIC_FILTERS
   Angle_3
   angle_3_object() const