/usr/share/acl2-7.1/books/acl2s/ is in acl2-books 7.1-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/acl2-7.1/books/acl2s/base-theory.o
/usr/share/acl2-7.1/books/acl2s/ccg/
/usr/share/acl2-7.1/books/acl2s/ccg/ccg-settings-dependencies.o
/usr/share/acl2-7.1/books/acl2s/cgen/
/usr/share/acl2-7.1/books/acl2s/cgen/acl2s-parameter.o
/usr/share/acl2-7.1/books/acl2s/cgen/basis.o
/usr/share/acl2-7.1/books/acl2s/cgen/build-enumcalls.o
/usr/share/acl2-7.1/books/acl2s/cgen/callback.o
/usr/share/acl2-7.1/books/acl2s/cgen/cgen-search.o
/usr/share/acl2-7.1/books/acl2s/cgen/prove-cgen.o
/usr/share/acl2-7.1/books/acl2s/cgen/random.o
/usr/share/acl2-7.1/books/acl2s/cgen/simple-graph-array.o
/usr/share/acl2-7.1/books/acl2s/cgen/top.o
/usr/share/acl2-7.1/books/acl2s/cgen/type.o
/usr/share/acl2-7.1/books/acl2s/cgen/utilities.o
/usr/share/acl2-7.1/books/acl2s/cgen/with-timeout.o
/usr/share/acl2-7.1/books/acl2s/custom.o
/usr/share/acl2-7.1/books/acl2s/defdata/
/usr/share/acl2-7.1/books/acl2s/defdata/alistof.o
/usr/share/acl2-7.1/books/acl2s/defdata/base.o
/usr/share/acl2-7.1/books/acl2s/defdata/builtin-combinators.o
/usr/share/acl2-7.1/books/acl2s/defdata/defdata-core.o
/usr/share/acl2-7.1/books/acl2s/defdata/defdata-util.o
/usr/share/acl2-7.1/books/acl2s/defdata/enumerators-gen.o
/usr/share/acl2-7.1/books/acl2s/defdata/library-support.o
/usr/share/acl2-7.1/books/acl2s/defdata/listof.o
/usr/share/acl2-7.1/books/acl2s/defdata/map.o
/usr/share/acl2-7.1/books/acl2s/defdata/mv-proof.o
/usr/share/acl2-7.1/books/acl2s/defdata/num-list-fns.o
/usr/share/acl2-7.1/books/acl2s/defdata/num-list-thms.o
/usr/share/acl2-7.1/books/acl2s/defdata/random-state-basis1.o
/usr/share/acl2-7.1/books/acl2s/defdata/random-state.o
/usr/share/acl2-7.1/books/acl2s/defdata/record.o
/usr/share/acl2-7.1/books/acl2s/defdata/register-combinator.o
/usr/share/acl2-7.1/books/acl2s/defdata/register-data-constructor.o
/usr/share/acl2-7.1/books/acl2s/defdata/register-type.o
/usr/share/acl2-7.1/books/acl2s/defdata/rem-and-floor.o
/usr/share/acl2-7.1/books/acl2s/defdata/sig.o
/usr/share/acl2-7.1/books/acl2s/defdata/splitnat.o
/usr/share/acl2-7.1/books/acl2s/defdata/switchnat.o
/usr/share/acl2-7.1/books/acl2s/defdata/tau-characterization.o
/usr/share/acl2-7.1/books/acl2s/defdata/top.o
/usr/share/acl2-7.1/books/acl2s/defdata/var-book.o
/usr/share/acl2-7.1/books/acl2s/defunc.o
/usr/share/acl2-7.1/books/acl2s/doc.o
/usr/share/acl2-7.1/books/acl2s/portcullis.o