/usr/share/acl2-7.1/books/demos/gl-and-use-example.o is in acl2-books 7.1-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/acl2-7.1/books/demos/../../../../lib/acl2-7.1/books/demos/gl-and-use-example.o