/usr/share/acl2-8.0dfsg/books/centaur/fty/ is in acl2-books-source 8.0dfsg-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/acl2-8.0dfsg/books/centaur/fty/baselists.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/basetypes.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/bitstruct-theory.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/bitstruct.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/cert.acl2
/usr/share/acl2-8.0dfsg/books/centaur/fty/database.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/deftypes.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/docgen.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/fixequiv.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/fixtype.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/fty-alist.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/fty-list.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/fty-parseutils.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/fty-sugar.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/fty-sum.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/fty-transsum.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/portcullis.acl2
/usr/share/acl2-8.0dfsg/books/centaur/fty/portcullis.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/tests/
/usr/share/acl2-8.0dfsg/books/centaur/fty/tests/cert.acl2
/usr/share/acl2-8.0dfsg/books/centaur/fty/tests/defprod-scale.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/tests/deftagsum-scale.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/tests/deftranssum.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/tests/doc.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/tests/fixequiv.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/tests/simple.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/tests/terms.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/tests/top.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/tests/utils.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/tests/visitor.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/top.lisp
/usr/share/acl2-8.0dfsg/books/centaur/fty/visitor.lisp