/usr/include/sc/math/ is in libsc-dev 2.3.1-18+deb9u1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/sc/math/isosurf/
/usr/include/sc/math/isosurf/LIBS.h
/usr/include/sc/math/isosurf/edge.h
/usr/include/sc/math/isosurf/implicit.h
/usr/include/sc/math/isosurf/isosurf.h
/usr/include/sc/math/isosurf/shape.h
/usr/include/sc/math/isosurf/surf.h
/usr/include/sc/math/isosurf/triangle.h
/usr/include/sc/math/isosurf/tricoef.h
/usr/include/sc/math/isosurf/vertex.h
/usr/include/sc/math/isosurf/volume.h
/usr/include/sc/math/isosurf/volume_i.h
/usr/include/sc/math/optimize/
/usr/include/sc/math/optimize/LIBS.h
/usr/include/sc/math/optimize/conv.h
/usr/include/sc/math/optimize/diis.h
/usr/include/sc/math/optimize/efc.h
/usr/include/sc/math/optimize/function.h
/usr/include/sc/math/optimize/gdiis.h
/usr/include/sc/math/optimize/linkage.h
/usr/include/sc/math/optimize/mcsearch.h
/usr/include/sc/math/optimize/newton.h
/usr/include/sc/math/optimize/opt.h
/usr/include/sc/math/optimize/qnewton.h
/usr/include/sc/math/optimize/scextrap.h
/usr/include/sc/math/optimize/scextrapmat.h
/usr/include/sc/math/optimize/steep.h
/usr/include/sc/math/optimize/transform.h
/usr/include/sc/math/optimize/update.h
/usr/include/sc/math/scmat/
/usr/include/sc/math/scmat/LIBS.h
/usr/include/sc/math/scmat/abstract.h
/usr/include/sc/math/scmat/blkiter.h
/usr/include/sc/math/scmat/block.h
/usr/include/sc/math/scmat/blocked.h
/usr/include/sc/math/scmat/cmatrix.h
/usr/include/sc/math/scmat/dim.h
/usr/include/sc/math/scmat/dist.h
/usr/include/sc/math/scmat/disthql.h
/usr/include/sc/math/scmat/elemop.h
/usr/include/sc/math/scmat/f77sym.h
/usr/include/sc/math/scmat/linkage.h
/usr/include/sc/math/scmat/local.h
/usr/include/sc/math/scmat/matrix.h
/usr/include/sc/math/scmat/matrix3.h
/usr/include/sc/math/scmat/matrix_i.h
/usr/include/sc/math/scmat/mops.h
/usr/include/sc/math/scmat/offset.h
/usr/include/sc/math/scmat/repl.h
/usr/include/sc/math/scmat/result.h
/usr/include/sc/math/scmat/util.h
/usr/include/sc/math/scmat/vector3.h
/usr/include/sc/math/scmat/vector3_i.h
/usr/include/sc/math/symmetry/
/usr/include/sc/math/symmetry/LIBS.h
/usr/include/sc/math/symmetry/corrtab.h
/usr/include/sc/math/symmetry/pointgrp.h