/usr/include/CGAL/Surface_mesh_simplification/ is in libcgal-dev 4.2-5ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/CGAL/Surface_mesh_simplification/Detail/
/usr/include/CGAL/Surface_mesh_simplification/Detail/Common.h
/usr/include/CGAL/Surface_mesh_simplification/Detail/Edge_collapse.h
/usr/include/CGAL/Surface_mesh_simplification/Detail/Edge_collapse_impl.h
/usr/include/CGAL/Surface_mesh_simplification/Edge_collapse_visitor_base.h
/usr/include/CGAL/Surface_mesh_simplification/HalfedgeGraph_Polyhedron_3.h
/usr/include/CGAL/Surface_mesh_simplification/Policies/
/usr/include/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/
/usr/include/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Count_ratio_stop_predicate.h
/usr/include/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Count_stop_predicate.h
/usr/include/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Detail/
/usr/include/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Detail/Lindstrom_Turk_core.h
/usr/include/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Detail/Lindstrom_Turk_core_impl.h
/usr/include/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Edge_length_cost.h
/usr/include/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Edge_profile.h
/usr/include/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Edge_profile_impl.h
/usr/include/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/LindstromTurk.h
/usr/include/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/LindstromTurk_cost.h
/usr/include/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/LindstromTurk_params.h
/usr/include/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/LindstromTurk_placement.h
/usr/include/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Midpoint_and_length.h
/usr/include/CGAL/Surface_mesh_simplification/Policies/Edge_collapse/Midpoint_placement.h
/usr/include/CGAL/Surface_mesh_simplification/edge_collapse.h
/usr/include/CGAL/Surface_mesh_simplification/halfedge_collapse_Polyhedron_3.h