/usr/share/acl2-6.5/books/centaur/esim/ is in acl2-books-source 6.5-2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/acl2-6.5/books/centaur/esim/cert.acl2
/usr/share/acl2-6.5/books/centaur/esim/esim-cut.lisp
/usr/share/acl2-6.5/books/centaur/esim/esim-paths.lisp
/usr/share/acl2-6.5/books/centaur/esim/esim-primitives.lisp
/usr/share/acl2-6.5/books/centaur/esim/esim-sexpr-correct.lisp
/usr/share/acl2-6.5/books/centaur/esim/esim-sexpr-support-thms.lisp
/usr/share/acl2-6.5/books/centaur/esim/esim-sexpr-support.lisp
/usr/share/acl2-6.5/books/centaur/esim/esim-sexpr.lisp
/usr/share/acl2-6.5/books/centaur/esim/esim-spec.lisp
/usr/share/acl2-6.5/books/centaur/esim/esim-vcd.lisp
/usr/share/acl2-6.5/books/centaur/esim/esim-vl.lisp
/usr/share/acl2-6.5/books/centaur/esim/follow-backwards.lisp
/usr/share/acl2-6.5/books/centaur/esim/local-theory.lisp
/usr/share/acl2-6.5/books/centaur/esim/plist.lisp
/usr/share/acl2-6.5/books/centaur/esim/portcullis.acl2
/usr/share/acl2-6.5/books/centaur/esim/portcullis.lisp
/usr/share/acl2-6.5/books/centaur/esim/steps.lisp
/usr/share/acl2-6.5/books/centaur/esim/stv/
/usr/share/acl2-6.5/books/centaur/esim/stv/cert.acl2
/usr/share/acl2-6.5/books/centaur/esim/stv/stv-compile.lisp
/usr/share/acl2-6.5/books/centaur/esim/stv/stv-debug.lisp
/usr/share/acl2-6.5/books/centaur/esim/stv/stv-decomp-proofs-better.lisp
/usr/share/acl2-6.5/books/centaur/esim/stv/stv-decomp-proofs-even-better.lisp
/usr/share/acl2-6.5/books/centaur/esim/stv/stv-decomp-proofs.lisp
/usr/share/acl2-6.5/books/centaur/esim/stv/stv-doc.lisp
/usr/share/acl2-6.5/books/centaur/esim/stv/stv-expand.lisp
/usr/share/acl2-6.5/books/centaur/esim/stv/stv-run.lisp
/usr/share/acl2-6.5/books/centaur/esim/stv/stv-sim.lisp
/usr/share/acl2-6.5/books/centaur/esim/stv/stv-top.lisp
/usr/share/acl2-6.5/books/centaur/esim/stv/stv-util.lisp
/usr/share/acl2-6.5/books/centaur/esim/stv/stv-widen.lisp
/usr/share/acl2-6.5/books/centaur/esim/stv/stv2c/
/usr/share/acl2-6.5/books/centaur/esim/stv/stv2c/cert.acl2
/usr/share/acl2-6.5/books/centaur/esim/stv/stv2c/stv2c.lisp
/usr/share/acl2-6.5/books/centaur/esim/stv/stv2c/top.lisp