/usr/share/acl2-8.0dfsg/books/projects/symbolic/ is in acl2-books-source 8.0dfsg-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/acl2-8.0dfsg/books/projects/symbolic/generic/
/usr/share/acl2-8.0dfsg/books/projects/symbolic/generic/assertions.lisp
/usr/share/acl2-8.0dfsg/books/projects/symbolic/generic/defsimulate.lisp
/usr/share/acl2-8.0dfsg/books/projects/symbolic/generic/factorial-jvm-correct.acl2
/usr/share/acl2-8.0dfsg/books/projects/symbolic/generic/factorial-jvm-correct.lisp
/usr/share/acl2-8.0dfsg/books/projects/symbolic/generic/measures.lisp
/usr/share/acl2-8.0dfsg/books/projects/symbolic/generic/partial-correctness.lisp
/usr/share/acl2-8.0dfsg/books/projects/symbolic/generic/tiny-fib-correct.lisp
/usr/share/acl2-8.0dfsg/books/projects/symbolic/generic/total-correctness.lisp
/usr/share/acl2-8.0dfsg/books/projects/symbolic/m5/
/usr/share/acl2-8.0dfsg/books/projects/symbolic/m5/demo.acl2
/usr/share/acl2-8.0dfsg/books/projects/symbolic/m5/demo.lisp
/usr/share/acl2-8.0dfsg/books/projects/symbolic/m5/utilities.acl2
/usr/share/acl2-8.0dfsg/books/projects/symbolic/m5/utilities.lisp
/usr/share/acl2-8.0dfsg/books/projects/symbolic/tiny-fib/
/usr/share/acl2-8.0dfsg/books/projects/symbolic/tiny-fib/defstobj+.lisp
/usr/share/acl2-8.0dfsg/books/projects/symbolic/tiny-fib/fib-def.lisp
/usr/share/acl2-8.0dfsg/books/projects/symbolic/tiny-fib/tiny-rewrites.lisp
/usr/share/acl2-8.0dfsg/books/projects/symbolic/tiny-fib/tiny.lisp
/usr/share/acl2-8.0dfsg/books/projects/symbolic/tiny-triangle/
/usr/share/acl2-8.0dfsg/books/projects/symbolic/tiny-triangle/tiny-triangle-correct.lisp
/usr/share/acl2-8.0dfsg/books/projects/symbolic/tiny-triangle/triangle-def.lisp