/usr/include/fflas-ffpack/ is in fflas-ffpack-common 1.6.0-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/fflas-ffpack/config-blas.h
/usr/include/fflas-ffpack/fflas/
/usr/include/fflas-ffpack/fflas-ffpack-configuration.h
/usr/include/fflas-ffpack/fflas-ffpack.h
/usr/include/fflas-ffpack/fflas/fflas.h
/usr/include/fflas-ffpack/fflas/fflas_bounds.inl
/usr/include/fflas-ffpack/fflas/fflas_faddm.inl
/usr/include/fflas-ffpack/fflas/fflas_faddm_src.inl
/usr/include/fflas-ffpack/fflas/fflas_faddmin_src.inl
/usr/include/fflas-ffpack/fflas/fflas_faxpy.inl
/usr/include/fflas-ffpack/fflas/fflas_fcopy.inl
/usr/include/fflas-ffpack/fflas/fflas_fdot.inl
/usr/include/fflas-ffpack/fflas/fflas_fgemm.inl
/usr/include/fflas-ffpack/fflas/fflas_fgemv.inl
/usr/include/fflas-ffpack/fflas/fflas_fger.inl
/usr/include/fflas-ffpack/fflas/fflas_ftrmm.inl
/usr/include/fflas-ffpack/fflas/fflas_ftrmm_src.inl
/usr/include/fflas-ffpack/fflas/fflas_ftrsm.inl
/usr/include/fflas-ffpack/fflas/fflas_ftrsm_src.inl
/usr/include/fflas-ffpack/fflas/fflas_ftrsv.inl
/usr/include/fflas-ffpack/ffpack/
/usr/include/fflas-ffpack/ffpack/ffpack.h
/usr/include/fflas-ffpack/ffpack/ffpack_charpoly.inl
/usr/include/fflas-ffpack/ffpack/ffpack_charpoly_danilevski.inl
/usr/include/fflas-ffpack/ffpack/ffpack_charpoly_kgfast.inl
/usr/include/fflas-ffpack/ffpack/ffpack_charpoly_kgfastgeneralized.inl
/usr/include/fflas-ffpack/ffpack/ffpack_charpoly_kglu.inl
/usr/include/fflas-ffpack/ffpack/ffpack_echelonforms.inl
/usr/include/fflas-ffpack/ffpack/ffpack_frobenius.inl
/usr/include/fflas-ffpack/ffpack/ffpack_krylovelim.inl
/usr/include/fflas-ffpack/ffpack/ffpack_ludivine.inl
/usr/include/fflas-ffpack/ffpack/ffpack_minpoly.inl
/usr/include/fflas-ffpack/ffpack/ffpack_minpoly_construct.inl
/usr/include/fflas-ffpack/field/
/usr/include/fflas-ffpack/field/field-general.h
/usr/include/fflas-ffpack/field/modular-balanced-double.h
/usr/include/fflas-ffpack/field/modular-balanced-float.h
/usr/include/fflas-ffpack/field/modular-balanced-int32.h
/usr/include/fflas-ffpack/field/modular-balanced-int64.h
/usr/include/fflas-ffpack/field/modular-balanced.h
/usr/include/fflas-ffpack/field/modular-double.h
/usr/include/fflas-ffpack/field/modular-float.h
/usr/include/fflas-ffpack/field/modular-int32.h
/usr/include/fflas-ffpack/field/modular-int64.h
/usr/include/fflas-ffpack/field/modular-positive.h
/usr/include/fflas-ffpack/field/modular-randiter.h
/usr/include/fflas-ffpack/field/nonzero-randiter.h
/usr/include/fflas-ffpack/field/unparametric.h
/usr/include/fflas-ffpack/utils/
/usr/include/fflas-ffpack/utils/Matio.h
/usr/include/fflas-ffpack/utils/args-parser.h
/usr/include/fflas-ffpack/utils/debug.h
/usr/include/fflas-ffpack/utils/print-utils.h