anchor.diff:                                         (car (push (route-booking refmark cited node cont) modbook)))
                                         ((eq mark citedmark) (funcall cont)))))
                      (stack-ref-booking cited node cont cur))))
  -             (booking-as-lost (rroute node)
  +             (booking-as-lost (rroute node cont)
                  (multiple-value-bind (booking relation mark)
                    (check-booking rroute basebook)
  +                 (declare (ignore mark))
                    (if booking
                      (case relation
  -                     (:direct (cond ((eq mark citedmark) booking)
  -                                    (t (error t "~&Something wrong!~%"))))
  -                     (t (error t "~&Something wrong!~%")))
  +                     (:direct booking)
  +                     (:partly (funcall cont)))
                      (car (push (route-booking lostmark rroute node) basebook)))))
                (stack-ref-booking (cited node cont cur)
                  (and cur (push (route-booking citedmark cur node nil cited) basebook))
  
positive.code:                  (acond ((equal mnode bnode)
                           (booking-as-ref rroute bnode cont))
                          ((find-ref-candidates mnode rroute allowed-distance base)
                           (list (booking-as-lost rroute bnode)
                                 (booking-as-ref it mnode cont rroute)))
                          ((and (not (proper-list-p bnode)) (not (proper-list-p mnode)))
                           (list (booking-as-lost rroute bnode)
                                 mnode))
                          (t next-level)))
                  ((invalid-p bnode)
  
negative.code:                         ((proper-list-p mnode) next-level)
                          (t (list mnode))))
                  ((invalid-p mnode)
                   (booking-as-lost rroute bnode cont))))))))
  
  (defun refnode-p (node refmark)
    (and (proper-list-p node) (eq (car node) refmark)))
  