/usr/share/acl2-8.0dfsg/books/system/pcert/ is in acl2-books-source 8.0dfsg-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/acl2-8.0dfsg/books/system/pcert/acl2x-pcert-test-1.acl2
/usr/share/acl2-8.0dfsg/books/system/pcert/acl2x-pcert-test-1.lisp
/usr/share/acl2-8.0dfsg/books/system/pcert/acl2x-pcert-test-2-include.lisp
/usr/share/acl2-8.0dfsg/books/system/pcert/acl2x-pcert-test-2.acl2
/usr/share/acl2-8.0dfsg/books/system/pcert/acl2x-pcert-test-2.lisp
/usr/share/acl2-8.0dfsg/books/system/pcert/cert.acl2
/usr/share/acl2-8.0dfsg/books/system/pcert/elide-test.lisp
/usr/share/acl2-8.0dfsg/books/system/pcert/mid.acl2
/usr/share/acl2-8.0dfsg/books/system/pcert/mid.lisp
/usr/share/acl2-8.0dfsg/books/system/pcert/pkg-test.acl2
/usr/share/acl2-8.0dfsg/books/system/pcert/pkg-test.lisp
/usr/share/acl2-8.0dfsg/books/system/pcert/sub.lisp
/usr/share/acl2-8.0dfsg/books/system/pcert/top.acl2
/usr/share/acl2-8.0dfsg/books/system/pcert/top.lisp