/usr/share/acl2-8.0dfsg/books/coi/dtrees/ is in acl2-books-source 8.0dfsg-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/acl2-8.0dfsg/books/coi/dtrees/base.lisp
/usr/share/acl2-8.0dfsg/books/coi/dtrees/cert.acl2
/usr/share/acl2-8.0dfsg/books/coi/dtrees/child.lisp
/usr/share/acl2-8.0dfsg/books/coi/dtrees/deps.lisp
/usr/share/acl2-8.0dfsg/books/coi/dtrees/dtree-examples.lisp
/usr/share/acl2-8.0dfsg/books/coi/dtrees/equiv.lisp
/usr/share/acl2-8.0dfsg/books/coi/dtrees/erase.lisp
/usr/share/acl2-8.0dfsg/books/coi/dtrees/leafp.lisp
/usr/share/acl2-8.0dfsg/books/coi/dtrees/portcullis.acl2
/usr/share/acl2-8.0dfsg/books/coi/dtrees/portcullis.lisp
/usr/share/acl2-8.0dfsg/books/coi/dtrees/raw.lisp
/usr/share/acl2-8.0dfsg/books/coi/dtrees/royalp.lisp
/usr/share/acl2-8.0dfsg/books/coi/dtrees/set.lisp
/usr/share/acl2-8.0dfsg/books/coi/dtrees/top.lisp