anchor.diff:                    (declare (role role))
                     (when (and (eq message (role-message role))
                                (= index (the fixnum (role-position role))))
  -                    (let ((reply (role-reply role)) contained-reply)
  +                    (let ((reply (role-reply role)) boxed-reply)
                         (aif (find reply discovered-replies
  -                                 :key #'reply-container-reply :test #'eq)
  -                           (setf contained-reply it)
  -                           (push (setf contained-reply (contain-reply reply))
  -                                 discovered-replies))
  -                      (setf (elt (reply-container-rank contained-reply) index)
  -                            hierarchy-position)
  -                      (when (fully-specified-p (reply-container-rank contained-reply))
  -                        (unless (find reply contained-applicable-replies
  -                                      :key #'reply-container-reply :test #'eq)
  -                          (push contained-reply contained-applicable-replies)))))))
  +                                 :key #'unbox-ranked-reply :test #'eq)
  +                           (setf boxed-reply it)
  +                           (push (setf boxed-reply (box-reply reply)) discovered-replies))
  +                      (setf (svref boxed-reply (the fixnum (1+ index))) hierarchy-position)
  +                      (when (fully-specified-p boxed-reply)
  +                        (unless (find reply boxed-applicable-replies
  +                                      :key #'unbox-ranked-reply :test #'eq)
  +                          (push boxed-reply boxed-applicable-replies)))))))
            finally
  -           (if contained-applicable-replies
  -               (return (nunbox-replies (sort-applicable-replies contained-applicable-replies)))
  +           (if boxed-applicable-replies
  +               (return (nunbox-replies (sort-applicable-replies boxed-applicable-replies)))
                  (when errorp
                    (error 'no-applicable-replies :message (message-name message) :args args))))))
  
positive.code: ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  (in-package :sheeple)
  
  (defstruct (reply-container (:type vector))
    reply rank)
  
  (defun reply-specialized-length (reply)
    (count-required-parameters (reply-lambda-list reply)))
  
  (defun contain-reply (reply)
    (make-reply-container
     :reply reply
     :rank (make-vector (reply-specialized-length reply))))
  
  (defun nunbox-replies (replies)
    "Unbox in-place each of the contained REPLIES."
  
negative.code:             (compute-primary-erfun (cdr replies)))))
  
  (defun find-applicable-replies (message args &optional (errorp t))
    "Returns a sorted list of replies on MESSAGE for which appropriate roles
  are present in ARGS. If no such replies are found and ERRORP is true, a
  condition of type `no-applicable-replies' is signaled."
    (if (null args)
        (message-replies message)
        (loop with discovered-replies list and boxed-applicable-replies list
           for arg in args and index fixnum upfrom 0 do
             (loop
                for hierarchy-object in
  