/usr/share/acl2-6.3/books/clause-processors/ is in acl2-books-certs 6.3-5.
This file is owned by root:root, with mode 0o755.
..
/usr/share/acl2-6.3/books/clause-processors/autohide.cert
/usr/share/acl2-6.3/books/clause-processors/basic-examples.cert
/usr/share/acl2-6.3/books/clause-processors/bv-add-common.cert
/usr/share/acl2-6.3/books/clause-processors/bv-add-tests.cert
/usr/share/acl2-6.3/books/clause-processors/bv-add.cert
/usr/share/acl2-6.3/books/clause-processors/constant-prop.cert
/usr/share/acl2-6.3/books/clause-processors/decomp-hint.cert
/usr/share/acl2-6.3/books/clause-processors/deps-SULFA.cert
/usr/share/acl2-6.3/books/clause-processors/equality.cert
/usr/share/acl2-6.3/books/clause-processors/ev-find-rules.cert
/usr/share/acl2-6.3/books/clause-processors/ev-theoremp.cert
/usr/share/acl2-6.3/books/clause-processors/find-matching.cert
/usr/share/acl2-6.3/books/clause-processors/find-subterms.cert
/usr/share/acl2-6.3/books/clause-processors/generalize.cert
/usr/share/acl2-6.3/books/clause-processors/instantiate.cert
/usr/share/acl2-6.3/books/clause-processors/join-thms.cert
/usr/share/acl2-6.3/books/clause-processors/just-expand.cert
/usr/share/acl2-6.3/books/clause-processors/let-abstraction.cert
/usr/share/acl2-6.3/books/clause-processors/magic-ev.cert
/usr/share/acl2-6.3/books/clause-processors/meta-extract-simple-test.cert
/usr/share/acl2-6.3/books/clause-processors/meta-extract-user.cert
/usr/share/acl2-6.3/books/clause-processors/multi-env-trick.cert
/usr/share/acl2-6.3/books/clause-processors/null-fail-hints.cert
/usr/share/acl2-6.3/books/clause-processors/nvalues-thms.cert
/usr/share/acl2-6.3/books/clause-processors/replace-defined-consts.cert
/usr/share/acl2-6.3/books/clause-processors/replace-equalities.cert
/usr/share/acl2-6.3/books/clause-processors/replace-impl.cert
/usr/share/acl2-6.3/books/clause-processors/stobj-preservation.cert
/usr/share/acl2-6.3/books/clause-processors/sublis-var-meaning.cert
/usr/share/acl2-6.3/books/clause-processors/term-patterns.cert
/usr/share/acl2-6.3/books/clause-processors/unify-subst.cert
/usr/share/acl2-6.3/books/clause-processors/use-by-hint.cert
/usr/share/acl2-6.3/books/clause-processors/witness-cp.cert