/usr/share/acl2-7.2dfsg/books/system/doc/ is in acl2-books-source 7.2dfsg-3.
This file is owned by root:root, with mode 0o755.
..
/usr/share/acl2-7.2dfsg/books/system/doc/acl2-doc-wrap.lisp
/usr/share/acl2-7.2dfsg/books/system/doc/acl2-doc.lisp
/usr/share/acl2-7.2dfsg/books/system/doc/acl2-manual.lisp
/usr/share/acl2-7.2dfsg/books/system/doc/cert.acl2
/usr/share/acl2-7.2dfsg/books/system/doc/convert-legacy-doc/
/usr/share/acl2-7.2dfsg/books/system/doc/convert-legacy-doc/cert.acl2
/usr/share/acl2-7.2dfsg/books/system/doc/convert-legacy-doc/export-acl2doc.lisp
/usr/share/acl2-7.2dfsg/books/system/doc/convert-legacy-doc/import-acl2doc.lisp
/usr/share/acl2-7.2dfsg/books/system/doc/convert-legacy-doc/write-acl2-xdoc.lisp
/usr/share/acl2-7.2dfsg/books/system/doc/portcullis.acl2
/usr/share/acl2-7.2dfsg/books/system/doc/portcullis.lisp
/usr/share/acl2-7.2dfsg/books/system/doc/render-doc-base.lisp
/usr/share/acl2-7.2dfsg/books/system/doc/render-doc.lisp