/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/ is in acl2-books-source 7.2dfsg-3.
This file is owned by root:root, with mode 0o755.
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/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/eisenstein.lisp
/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/euclid.lisp
/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/euler.lisp
/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/fermat.lisp
/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/gauss.lisp
/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/mersenne.lisp
/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/pratt.lisp
/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/support/
/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/support/eisenstein.lisp
/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/support/euclid.lisp
/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/support/euler.lisp
/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/support/fermat.lisp
/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/support/gauss.lisp
/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/support/mersenne.lisp
/usr/share/acl2-7.2dfsg/books/projects/quadratic-reciprocity/support/pratt.lisp