/usr/share/acl2-6.3/books/centaur/aig/ is in acl2-books-source 6.3-5.
This file is owned by root:root, with mode 0o755.
..
/usr/share/acl2-6.3/books/centaur/aig/accumulate-nodes-vars.lisp
/usr/share/acl2-6.3/books/centaur/aig/aig-base.lisp
/usr/share/acl2-6.3/books/centaur/aig/aig-equivs.lisp
/usr/share/acl2-6.3/books/centaur/aig/aig-print.lisp
/usr/share/acl2-6.3/books/centaur/aig/aig-sat-tests.lisp
/usr/share/acl2-6.3/books/centaur/aig/aig-sat.lisp
/usr/share/acl2-6.3/books/centaur/aig/aig-vars-ext.lisp
/usr/share/acl2-6.3/books/centaur/aig/aig-vars-fast.lisp
/usr/share/acl2-6.3/books/centaur/aig/aig-vars.lisp
/usr/share/acl2-6.3/books/centaur/aig/aig2c.lisp
/usr/share/acl2-6.3/books/centaur/aig/aiger.lisp
/usr/share/acl2-6.3/books/centaur/aig/base.lisp
/usr/share/acl2-6.3/books/centaur/aig/bddify-correct.lisp
/usr/share/acl2-6.3/books/centaur/aig/bddify.lisp
/usr/share/acl2-6.3/books/centaur/aig/best-aig.lisp
/usr/share/acl2-6.3/books/centaur/aig/cert.acl2
/usr/share/acl2-6.3/books/centaur/aig/eval-restrict.lisp
/usr/share/acl2-6.3/books/centaur/aig/faig-base.lisp
/usr/share/acl2-6.3/books/centaur/aig/faig-constructors.lisp
/usr/share/acl2-6.3/books/centaur/aig/faig-equivs.lisp
/usr/share/acl2-6.3/books/centaur/aig/faig-purebool-p.lisp
/usr/share/acl2-6.3/books/centaur/aig/g-aig-eval.acl2
/usr/share/acl2-6.3/books/centaur/aig/g-aig-eval.lisp
/usr/share/acl2-6.3/books/centaur/aig/induction.lisp
/usr/share/acl2-6.3/books/centaur/aig/misc.lisp
/usr/share/acl2-6.3/books/centaur/aig/portcullis.acl2
/usr/share/acl2-6.3/books/centaur/aig/portcullis.lisp
/usr/share/acl2-6.3/books/centaur/aig/random-sim.lisp
/usr/share/acl2-6.3/books/centaur/aig/three-four.lisp
/usr/share/acl2-6.3/books/centaur/aig/top.lisp
/usr/share/acl2-6.3/books/centaur/aignet/aig-cnf.lisp
/usr/share/acl2-6.3/books/centaur/aignet/aig-sim.lisp
/usr/share/acl2-6.3/books/centaur/aignet/aignet-absstobj.lisp
/usr/share/acl2-6.3/books/centaur/aignet/aignet-exec-thms.lisp
/usr/share/acl2-6.3/books/centaur/aignet/aignet-exec.lisp
/usr/share/acl2-6.3/books/centaur/aignet/aignet-logic-interface.lisp
/usr/share/acl2-6.3/books/centaur/aignet/aignet-logic.lisp
/usr/share/acl2-6.3/books/centaur/aignet/arrays.lisp
/usr/share/acl2-6.3/books/centaur/aignet/bit-lemmas.lisp
/usr/share/acl2-6.3/books/centaur/aignet/cert.acl2
/usr/share/acl2-6.3/books/centaur/aignet/cnf.lisp
/usr/share/acl2-6.3/books/centaur/aignet/construction.lisp
/usr/share/acl2-6.3/books/centaur/aignet/copying.lisp
/usr/share/acl2-6.3/books/centaur/aignet/eval.lisp
/usr/share/acl2-6.3/books/centaur/aignet/from-hons-aig-fast.lisp
/usr/share/acl2-6.3/books/centaur/aignet/from-hons-aig.lisp
/usr/share/acl2-6.3/books/centaur/aignet/litp.lisp
/usr/share/acl2-6.3/books/centaur/aignet/portcullis.acl2
/usr/share/acl2-6.3/books/centaur/aignet/portcullis.lisp
/usr/share/acl2-6.3/books/centaur/aignet/prune.lisp
/usr/share/acl2-6.3/books/centaur/aignet/refcounts.lisp
/usr/share/acl2-6.3/books/centaur/aignet/semantics.lisp
/usr/share/acl2-6.3/books/centaur/aignet/snodes.lisp
/usr/share/acl2-6.3/books/centaur/aignet/to-hons-aig.lisp
/usr/share/acl2-6.3/books/centaur/aignet/types.lisp
/usr/share/acl2-6.3/books/centaur/aignet/vecsim.lisp