/usr/share/acl2-8.0dfsg/books/projects/concurrent-programs/ is in acl2-books-source 8.0dfsg-1.
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/usr/share/acl2-8.0dfsg/books/projects/concurrent-programs/bakery/
/usr/share/acl2-8.0dfsg/books/projects/concurrent-programs/bakery/apply-total-order.lisp
/usr/share/acl2-8.0dfsg/books/projects/concurrent-programs/bakery/fairenv.lisp
/usr/share/acl2-8.0dfsg/books/projects/concurrent-programs/bakery/final-theorems.lisp
/usr/share/acl2-8.0dfsg/books/projects/concurrent-programs/bakery/initial-state.lisp
/usr/share/acl2-8.0dfsg/books/projects/concurrent-programs/bakery/inv-persists.lisp
/usr/share/acl2-8.0dfsg/books/projects/concurrent-programs/bakery/inv-sufficient.lisp
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/usr/share/acl2-8.0dfsg/books/projects/concurrent-programs/bakery/properties-of-sets.lisp
/usr/share/acl2-8.0dfsg/books/projects/concurrent-programs/bakery/properties.lisp
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/usr/share/acl2-8.0dfsg/books/projects/concurrent-programs/bakery/stutter1-match.lisp
/usr/share/acl2-8.0dfsg/books/projects/concurrent-programs/bakery/stutter2.lisp
/usr/share/acl2-8.0dfsg/books/projects/concurrent-programs/bakery/variables.lisp