/usr/ is in libpari-dev 2.9.4-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/
/usr/include/x86_64-linux-gnu/
/usr/include/x86_64-linux-gnu/pari/
/usr/include/x86_64-linux-gnu/pari/mpinl.h
/usr/include/x86_64-linux-gnu/pari/pari.h
/usr/include/x86_64-linux-gnu/pari/paricast.h
/usr/include/x86_64-linux-gnu/pari/paricfg.h
/usr/include/x86_64-linux-gnu/pari/paricom.h
/usr/include/x86_64-linux-gnu/pari/paridecl.h
/usr/include/x86_64-linux-gnu/pari/parierr.h
/usr/include/x86_64-linux-gnu/pari/parigen.h
/usr/include/x86_64-linux-gnu/pari/pariinl.h
/usr/include/x86_64-linux-gnu/pari/parimt.h
/usr/include/x86_64-linux-gnu/pari/parinf.h
/usr/include/x86_64-linux-gnu/pari/pariold.h
/usr/include/x86_64-linux-gnu/pari/paripriv.h
/usr/include/x86_64-linux-gnu/pari/paristio.h
/usr/include/x86_64-linux-gnu/pari/parisys.h
/usr/include/x86_64-linux-gnu/pari/paritune.h
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/libpari.a
/usr/lib/x86_64-linux-gnu/pari/
/usr/lib/x86_64-linux-gnu/pari/pari.cfg
/usr/lib/x86_64-linux-gnu/pari/pari.cfg.dbg
/usr/share/
/usr/share/doc/
/usr/share/doc/libpari-dev/
/usr/share/doc/libpari-dev/copyright
/usr/share/pari/
/usr/share/pari/PARI/
/usr/share/pari/PARI/822.pm
/usr/share/pari/pari.desc
/usr/include/x86_64-linux-gnu/pari/genpari.h
/usr/lib/x86_64-linux-gnu/libpari.so
/usr/share/doc/libpari-dev/changelog.Debian.gz