diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/algebraic_curves.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/algebraic_curves.cpp
index f8bc222897b..bb113edd04d 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/algebraic_curves.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/algebraic_curves.cpp
@@ -14,7 +14,6 @@ int main ()
 
 #else
 
-#include <CGAL/basic.h>
 #include <CGAL/Arrangement_2.h>
 #include <CGAL/Arr_algebraic_segment_traits_2.h>
 
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/algebraic_segments.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/algebraic_segments.cpp
index aba48b9f222..1665af18e8f 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/algebraic_segments.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/algebraic_segments.cpp
@@ -14,7 +14,6 @@ int main ()
 }
 #else
 
-#include <CGAL/basic.h>
 #include <CGAL/Arrangement_2.h>
 #include <CGAL/Arr_algebraic_segment_traits_2.h>
 
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/batched_point_location.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/batched_point_location.cpp
index a88e118f38c..1e4ff25b9af 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/batched_point_location.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/batched_point_location.cpp
@@ -4,7 +4,6 @@
 #include <list>
 #include <vector>
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_batched_point_location.h>
 
 #include "arr_inexact_construction_segments.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bounded_vertical_decomposition.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bounded_vertical_decomposition.cpp
index 77137ced487..c7b0621eace 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bounded_vertical_decomposition.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/bounded_vertical_decomposition.cpp
@@ -3,7 +3,6 @@
 
 #include <list>
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_vertical_decomposition_2.h>
 
 #include "arr_exact_construction_segments.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/conic_multiplicities.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/conic_multiplicities.cpp
index 5eaccf5db9e..fdb8852661d 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/conic_multiplicities.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/conic_multiplicities.cpp
@@ -5,7 +5,6 @@
 
 #ifdef CGAL_USE_CORE
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_naive_point_location.h>
 
 #include "arr_conics.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/consolidated_curve_data.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/consolidated_curve_data.cpp
index 55ea5aada14..86a07143360 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/consolidated_curve_data.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/consolidated_curve_data.cpp
@@ -2,7 +2,6 @@
 // Associating a color attribute with segments using the consolidated
 // curve-data traits.
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_consolidated_curve_data_traits_2.h>
 
 #include "arr_exact_construction_segments.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/curve_history.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/curve_history.cpp
index 4a7b7a57bdb..06c2b6b3f8b 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/curve_history.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/curve_history.cpp
@@ -1,7 +1,6 @@
 //! \file examples/Arrangement_on_surface_2/curve_history.cpp
 // Constructing an arrangement with curve history.
 
-#include <CGAL/basic.h>
 #include <CGAL/Arrangement_with_history_2.h>
 #include <CGAL/Arr_trapezoid_ric_point_location.h>
 
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension.cpp
index 88140318fd2..63fec621829 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension.cpp
@@ -1,7 +1,6 @@
 //! \file examples/Arrangement_on_surface_2/dcel_extension.cpp
 // Extending all DCEL records (vertices, edges and faces).
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_extended_dcel.h>
 
 #include "arr_exact_construction_segments.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension_io.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension_io.cpp
index 441e4f7b6ca..5dab64d1041 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension_io.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dcel_extension_io.cpp
@@ -3,7 +3,6 @@
 
 #include <fstream>
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_extended_dcel.h>
 #include <CGAL/IO/Arr_iostream.h>
 #include <CGAL/IO/Arr_text_formatter.h>
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dual_with_data.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dual_with_data.cpp
index 8ffb6688971..996728bd717 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dual_with_data.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/dual_with_data.cpp
@@ -4,7 +4,6 @@
 
 #include <algorithm>
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_curve_data_traits_2.h>
 
 #include "arr_linear.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/edge_manipulation_curve_history.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/edge_manipulation_curve_history.cpp
index bf1d504d4f6..92f8d96c893 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/edge_manipulation_curve_history.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/edge_manipulation_curve_history.cpp
@@ -1,7 +1,6 @@
 //! \file examples/Arrangement_on_surface_2/edge_manipulation_curve_history.cpp
 // Removing curves and manipulating edges in an arrangement with history.
 
-#include <CGAL/basic.h>
 #include <CGAL/Arrangement_with_history_2.h>
 #include <CGAL/Arr_walk_along_line_point_location.h>
 
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/ellipses.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/ellipses.cpp
index bc2403f2aeb..480b0eefe31 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/ellipses.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/ellipses.cpp
@@ -5,7 +5,6 @@
 
 #ifdef CGAL_USE_CORE
 
-#include <CGAL/basic.h>
 #include <CGAL/draw_arrangement_2.h>
 
 #include "arr_conics.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/face_extension.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/face_extension.cpp
index d1bdaa8bb38..9850df520c4 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/face_extension.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/face_extension.cpp
@@ -1,7 +1,6 @@
 //! \file examples/Arrangement_on_surface_2/face_extension.cpp
 // Extending the arrangement-face records.
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_extended_dcel.h>
 #include <CGAL/Arr_observer.h>
 
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/face_extension_overlay.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/face_extension_overlay.cpp
index 27459e6ff9e..255e4473822 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/face_extension_overlay.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/face_extension_overlay.cpp
@@ -3,7 +3,6 @@
 
 #include <cassert>
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_overlay_2.h>
 #include <CGAL/Arr_default_overlay_traits.h>
 
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/generic_curve_data.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/generic_curve_data.cpp
index 72710580dee..55ac76ffb59 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/generic_curve_data.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/generic_curve_data.cpp
@@ -2,7 +2,6 @@
 // Associating a name attribute with segments using the generic curve-data
 // traits.
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_curve_data_traits_2.h>
 
 #include "arr_polylines.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/hyperbolas.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/hyperbolas.cpp
index aa68c6c247f..8c165cac9f6 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/hyperbolas.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/hyperbolas.cpp
@@ -5,7 +5,6 @@
 
 #ifdef CGAL_USE_CORE
 
-#include <CGAL/basic.h>
 #include <CGAL/draw_arrangement_2.h>
 
 #include "arr_conics.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/incremental_insertion.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/incremental_insertion.cpp
index 857a5ecdf01..a2d4c8e7f43 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/incremental_insertion.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/incremental_insertion.cpp
@@ -1,7 +1,6 @@
 //! \file examples/Arrangement_on_surface_2/incremental_insertion.cpp
 // Using the global incremental insertion functions.
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_naive_point_location.h>
 
 #include "arr_exact_construction_segments.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io.cpp
index 4e38086f3ab..05f95776038 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io.cpp
@@ -3,7 +3,6 @@
 
 #include <fstream>
 
-#include <CGAL/basic.h>
 #include <CGAL/IO/Arr_iostream.h>
 
 #include "arr_inexact_construction_segments.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_curve_history.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_curve_history.cpp
index b62c6a93ff9..6a37fd24094 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_curve_history.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_curve_history.cpp
@@ -3,7 +3,6 @@
 
 #include <fstream>
 
-#include <CGAL/basic.h>
 #include <CGAL/Arrangement_with_history_2.h>
 #include <CGAL/IO/Arr_with_history_iostream.h>
 
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_unbounded.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_unbounded.cpp
index 5cf95522f18..1cb4d2161a8 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_unbounded.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/io_unbounded.cpp
@@ -4,7 +4,6 @@
 #include <list>
 #include <fstream>
 
-#include <CGAL/basic.h>
 #include <CGAL/IO/Arr_iostream.h>
 
 #include "arr_linear.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/linear_conics.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/linear_conics.cpp
index b0f990e0ee9..071c118052e 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/linear_conics.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/linear_conics.cpp
@@ -5,7 +5,6 @@
 
 #ifdef CGAL_USE_CORE
 
-#include <CGAL/basic.h>
 #include <CGAL/draw_arrangement_2.h>
 
 #include "arr_conics.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/observer.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/observer.cpp
index d4261d64dd2..88bbd31b83a 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/observer.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/observer.cpp
@@ -1,7 +1,6 @@
 //! \file examples/Arrangement_on_surface_2/observer.cpp
 // Using a simple arrangement observer.
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_observer.h>
 
 #include "arr_exact_construction_segments.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay.cpp
index 4f2fa8a38dd..30b0fd90a23 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay.cpp
@@ -1,7 +1,6 @@
 //! \file examples/Arrangement_on_surface_2/overlay.cpp
 // A simple overlay of two arrangements.
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_overlay_2.h>
 
 #include "arr_exact_construction_segments.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay_color.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay_color.cpp
index 42c7f69aaff..1009abe7d95 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay_color.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay_color.cpp
@@ -3,7 +3,6 @@
 
 #include <cassert>
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_extended_dcel.h>
 #include <CGAL/Arr_overlay_2.h>
 #include <CGAL/Arr_default_overlay_traits.h>
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay_unbounded.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay_unbounded.cpp
index 40d06f4f712..fd49d0fa95a 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay_unbounded.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/overlay_unbounded.cpp
@@ -3,7 +3,6 @@
 
 #include <string>
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_extended_dcel.h>
 #include <CGAL/Arr_overlay_2.h>
 #include <CGAL/Arr_default_overlay_traits.h>
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/parabolas.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/parabolas.cpp
index 2f3bf04bf61..7213b06f095 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/parabolas.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/parabolas.cpp
@@ -5,7 +5,6 @@
 
 #ifdef CGAL_USE_CORE
 
-#include <CGAL/basic.h>
 #include <CGAL/draw_arrangement_2.h>
 
 #include "arr_conics.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/point_location.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/point_location.cpp
index 8f9c0458d55..10fbb71ab83 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/point_location.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/point_location.cpp
@@ -1,7 +1,6 @@
 //! \file examples/Arrangement_on_surface_2/point_location.cpp
 // Answering point-location queries.
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_naive_point_location.h>
 #include <CGAL/Arr_landmarks_point_location.h>
 
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_bezier.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_bezier.cpp
index 309a849e64b..25c74a71836 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_bezier.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_bezier.cpp
@@ -13,7 +13,6 @@ int main() {
 
 #else
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_polycurve_traits_2.h>
 
 #include "arr_Bezier.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_circular_arc.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_circular_arc.cpp
index 742473a79bf..46432532c00 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_circular_arc.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_circular_arc.cpp
@@ -15,7 +15,6 @@ int main() {
 
 #include <vector>
 
-#include <CGAL/basic.h>
 #include <CGAL/CORE_algebraic_number_traits.h>
 #include <CGAL/Arr_polycurve_traits_2.h>
 
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_conic.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_conic.cpp
index bdaafb9ebb0..7910a723c46 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_conic.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/polycurve_conic.cpp
@@ -15,7 +15,6 @@ int main() {
 
 #include <vector>
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_polycurve_traits_2.h>
 
 #include "arr_conics.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/predefined_kernel.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/predefined_kernel.cpp
index f0ed969d845..d238706a0df 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/predefined_kernel.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/predefined_kernel.cpp
@@ -5,8 +5,6 @@
 #include <list>
 #include <chrono>
 
-#include <CGAL/basic.h>
-
 #include "arr_exact_construction_segments.h"
 #include "arr_print.h"
 #include "read_objects.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/spherical_overlay.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/spherical_overlay.cpp
index ba27599b22d..e43b1df9ab8 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/spherical_overlay.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/spherical_overlay.cpp
@@ -1,7 +1,6 @@
 //! \file examples/Arrangement_on_surface_2/spherical_overlay.cpp
 // Overlay of two arrangements embedded on the sphere.
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_overlay_2.h>
 #include <CGAL/Arr_default_overlay_traits.h>
 
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/tracing_counting.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/tracing_counting.cpp
index df5715628f7..1f2a4407b16 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/tracing_counting.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/tracing_counting.cpp
@@ -3,7 +3,6 @@
 
 #include <list>
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_tracing_traits_2.h>
 #include <CGAL/Arr_counting_traits_2.h>
 
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/unb_planar_vertical_decomposition.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/unb_planar_vertical_decomposition.cpp
index e870a714ccc..50ac2b19f3e 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/unb_planar_vertical_decomposition.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/unb_planar_vertical_decomposition.cpp
@@ -3,7 +3,6 @@
 
 #include <list>
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_vertical_decomposition_2.h>
 
 #include "arr_linear.h"
diff --git a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/vertical_ray_shooting.cpp b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/vertical_ray_shooting.cpp
index e4e415bd825..c1e80f97c82 100644
--- a/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/vertical_ray_shooting.cpp
+++ b/Arrangement_on_surface_2/examples/Arrangement_on_surface_2/vertical_ray_shooting.cpp
@@ -1,7 +1,6 @@
 //! \file examples/Arrangement_on_surface_2/ex_vertical_ray_shooting.cpp
 // Answering vertical ray-shooting queries.
 
-#include <CGAL/basic.h>
 #include <CGAL/Arr_walk_along_line_point_location.h>
 #include <CGAL/Arr_trapezoid_ric_point_location.h>
 
diff --git a/Kernel_23/examples/Kernel_23/MyKernel.cpp b/Kernel_23/examples/Kernel_23/MyKernel.cpp
index 834a22629b8..0894706db7b 100644
--- a/Kernel_23/examples/Kernel_23/MyKernel.cpp
+++ b/Kernel_23/examples/Kernel_23/MyKernel.cpp
@@ -1,4 +1,3 @@
-#include <CGAL/basic.h>
 #include <CGAL/Filtered_kernel.h>
 #include <CGAL/Delaunay_triangulation_2.h>
 #include <CGAL/squared_distance_2.h>
diff --git a/Segment_Delaunay_graph_2/test/Segment_Delaunay_graph_2/test_sdg_traits_2.cpp b/Segment_Delaunay_graph_2/test/Segment_Delaunay_graph_2/test_sdg_traits_2.cpp
index aabc32a7b35..57ed0cc3fd4 100644
--- a/Segment_Delaunay_graph_2/test/Segment_Delaunay_graph_2/test_sdg_traits_2.cpp
+++ b/Segment_Delaunay_graph_2/test/Segment_Delaunay_graph_2/test_sdg_traits_2.cpp
@@ -1,14 +1,11 @@
-#include <iostream>
-#include <fstream>
-#include <cassert>
-#include <vector>
 
-#include <CGAL/basic.h>
-#include <CGAL/Interval_arithmetic.h>
-#include <CGAL/Simple_cartesian.h>
+
 #include <CGAL/Segment_Delaunay_graph_traits_2.h>
 #include <CGAL/Segment_Delaunay_graph_filtered_traits_2.h>
 
+#include <CGAL/Interval_arithmetic.h>
+#include <CGAL/Simple_cartesian.h>
+
 #if defined(CGAL_USE_CORE) || defined(CGAL_USE_LEDA)
 #include <CGAL/Exact_algebraic.h>
 #endif
@@ -16,6 +13,10 @@
 #include <CGAL/Exact_rational.h>
 #include <CGAL/Exact_integer.h>
 
+#include <iostream>
+#include <fstream>
+#include <cassert>
+#include <vector>
 
 typedef CGAL::Simple_cartesian<double>      Double_Kernel;
 typedef CGAL::Simple_cartesian<CGAL::Interval_nt<true> >   IT_Kernel;