/usr/share/acl2-6.3/books/arithmetic-5/ is in acl2-books-certs 6.3-5.
This file is owned by root:root, with mode 0o755.
..
/usr/share/acl2-6.3/books/arithmetic-5/lib/
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/arithmetic-theory.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/banner.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/basic.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/building-blocks-helper.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/building-blocks.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/collect.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/common.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/default-hint.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/distributivity.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/dynamic-e-d.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/elim-hint.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/expt-helper.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/expt.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/forcing-types.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/if-normalization.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/integerp-helper.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/integerp-meta.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/integerp.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/mini-theories.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/natp-posp.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/normalize.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/numerator-and-denominator.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/remove-weak-inequalities.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/simple-equalities-and-inequalities-helper.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/simple-equalities-and-inequalities.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/simplify-helper.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/simplify.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/top.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/types-helper.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/types.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/basic-ops/we-are-here.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/floor-mod/
/usr/share/acl2-6.3/books/arithmetic-5/lib/floor-mod/floor-mod-basic-helper.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/floor-mod/floor-mod-basic.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/floor-mod/floor-mod-helper.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/floor-mod/floor-mod.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/floor-mod/forcing-types.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/floor-mod/if-normalization.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/floor-mod/logand-helper.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/floor-mod/logand.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/floor-mod/mod-expt-fast.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/floor-mod/more-floor-mod.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/floor-mod/top.cert
/usr/share/acl2-6.3/books/arithmetic-5/lib/floor-mod/truncate-rem.cert
/usr/share/acl2-6.3/books/arithmetic-5/support/
/usr/share/acl2-6.3/books/arithmetic-5/support/basic-arithmetic-helper.cert
/usr/share/acl2-6.3/books/arithmetic-5/support/basic-arithmetic.cert
/usr/share/acl2-6.3/books/arithmetic-5/support/expt-helper.cert
/usr/share/acl2-6.3/books/arithmetic-5/support/expt.cert
/usr/share/acl2-6.3/books/arithmetic-5/support/inequalities.cert
/usr/share/acl2-6.3/books/arithmetic-5/support/mini-theories.cert
/usr/share/acl2-6.3/books/arithmetic-5/support/non-linear.cert
/usr/share/acl2-6.3/books/arithmetic-5/support/num-and-denom-helper.cert
/usr/share/acl2-6.3/books/arithmetic-5/support/numerator-and-denominator.cert
/usr/share/acl2-6.3/books/arithmetic-5/support/prefer-times.cert
/usr/share/acl2-6.3/books/arithmetic-5/support/top.cert
/usr/share/acl2-6.3/books/arithmetic-5/top.cert