/usr/include/CGAL/predicates/ is in libcgal-dev 4.2-5ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/CGAL/predicates/Polygon_offset_pred_ftC2.h
/usr/include/CGAL/predicates/Regular_triangulation_ftC2.h
/usr/include/CGAL/predicates/Regular_triangulation_ftC3.h
/usr/include/CGAL/predicates/Regular_triangulation_rtH2.h
/usr/include/CGAL/predicates/Regular_triangulation_rtH3.h
/usr/include/CGAL/predicates/Straight_skeleton_pred_ftC2.h
/usr/include/CGAL/predicates/in_smallest_orthogonalcircle_ftC2.h
/usr/include/CGAL/predicates/kernel_ftC2.h
/usr/include/CGAL/predicates/kernel_ftC3.h
/usr/include/CGAL/predicates/predicates_for_mixed_complex_3.h
/usr/include/CGAL/predicates/predicates_for_voronoi_intersection_cartesian_2_3.h
/usr/include/CGAL/predicates/predicates_on_weighted_points_cartesian_3.h
/usr/include/CGAL/predicates/sign_of_determinant.h