/usr/include/CGAL/Arr_topology_traits/ is in libcgal-dev 4.2-5ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/CGAL/Arr_topology_traits/Arr_bounded_planar_batched_pl_helper.h
/usr/include/CGAL/Arr_topology_traits/Arr_bounded_planar_construction_helper.h
/usr/include/CGAL/Arr_topology_traits/Arr_bounded_planar_insertion_helper.h
/usr/include/CGAL/Arr_topology_traits/Arr_bounded_planar_overlay_helper.h
/usr/include/CGAL/Arr_topology_traits/Arr_bounded_planar_topology_traits_2_impl.h
/usr/include/CGAL/Arr_topology_traits/Arr_bounded_planar_vert_decomp_helper.h
/usr/include/CGAL/Arr_topology_traits/Arr_inc_insertion_zone_visitor.h
/usr/include/CGAL/Arr_topology_traits/Arr_planar_topology_traits_base_2.h
/usr/include/CGAL/Arr_topology_traits/Arr_spherical_batched_pl_helper.h
/usr/include/CGAL/Arr_topology_traits/Arr_spherical_construction_helper.h
/usr/include/CGAL/Arr_topology_traits/Arr_spherical_insertion_helper.h
/usr/include/CGAL/Arr_topology_traits/Arr_spherical_overlay_helper.h
/usr/include/CGAL/Arr_topology_traits/Arr_spherical_topology_traits_2_impl.h
/usr/include/CGAL/Arr_topology_traits/Arr_spherical_vert_decomp_helper.h
/usr/include/CGAL/Arr_topology_traits/Arr_unb_planar_batched_pl_helper.h
/usr/include/CGAL/Arr_topology_traits/Arr_unb_planar_construction_helper.h
/usr/include/CGAL/Arr_topology_traits/Arr_unb_planar_insertion_helper.h
/usr/include/CGAL/Arr_topology_traits/Arr_unb_planar_overlay_helper.h
/usr/include/CGAL/Arr_topology_traits/Arr_unb_planar_topology_traits_2_impl.h
/usr/include/CGAL/Arr_topology_traits/Arr_unb_planar_vert_decomp_helper.h