/usr/share/acl2-6.3/books/centaur/4v-sexpr/ is in acl2-books 6.3-5.
This file is owned by root:root, with mode 0o755.
..
/usr/share/acl2-6.3/books/centaur/4v-sexpr/4v-logic.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/bitspecs.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/compose-sexpr.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/g-sexpr-eval.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/nsexprs.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/onehot-rewrite.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/portcullis.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/sexpr-3v.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/sexpr-advanced.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/sexpr-building.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/sexpr-equivs.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/sexpr-eval.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/sexpr-fixpoint-correct.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/sexpr-fixpoint-rewriting.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/sexpr-fixpoint-spec.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/sexpr-fixpoint-top.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/sexpr-fixpoint.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/sexpr-loop-debug.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/sexpr-rewrites.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/sexpr-to-faig.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/sexpr-vars-1pass.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/sexpr-vars.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/svarmap.o
/usr/share/acl2-6.3/books/centaur/4v-sexpr/top.o