/usr/share/acl2-8.0dfsg/books/defexec/dag-unification/ is in acl2-books-source 8.0dfsg-1.
This file is owned by root:root, with mode 0o755.
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/usr/share/acl2-8.0dfsg/books/defexec/dag-unification/basic.lisp
/usr/share/acl2-8.0dfsg/books/defexec/dag-unification/dag-unification-l.lisp
/usr/share/acl2-8.0dfsg/books/defexec/dag-unification/dag-unification-rules.lisp
/usr/share/acl2-8.0dfsg/books/defexec/dag-unification/dag-unification-st.lisp
/usr/share/acl2-8.0dfsg/books/defexec/dag-unification/dags.lisp
/usr/share/acl2-8.0dfsg/books/defexec/dag-unification/list-unification-rules.lisp
/usr/share/acl2-8.0dfsg/books/defexec/dag-unification/matching.lisp
/usr/share/acl2-8.0dfsg/books/defexec/dag-unification/subsumption-subst.lisp
/usr/share/acl2-8.0dfsg/books/defexec/dag-unification/subsumption.lisp
/usr/share/acl2-8.0dfsg/books/defexec/dag-unification/terms-as-dag.lisp
/usr/share/acl2-8.0dfsg/books/defexec/dag-unification/terms-dag-stobj.lisp
/usr/share/acl2-8.0dfsg/books/defexec/dag-unification/terms.lisp