anchor.diff:            (progn
               (setf items (iter (for tag in base)
                                 (reducing (gethash tag tags) by #'result-id-intersection)
  -                              (remhash tag tags))) 
  +                              (remhash tag tags)))
               (iter (for (tag tag-items) in-hashtable tags)
                     (let ((new-items (intersection tag-items items :key #'result-id)))
                       (if new-items
                         (setf (gethash tag tags) new-items)
                         (remhash tag tags)))))
  -          
  +
             (setf items nearby))
  -                
   
           ; for each tag, number of contents + ordered list of subtags (up to 4)
  -        
           (values (iter (for (tag tag-items) in-hashtable tags)
                         (collect (list tag
                                        (length tag-items)
  
positive.code:               (dolist (stem newstems)
                  (push result (gethash stem *offer-stem-index*))))
  
            (when (eq type :request)          
              (with-locked-hash-table (*request-stem-index*)
                (dolist (stem oldstems)
                  (asetf (gethash stem *request-stem-index*)
  
negative.code:           (:span
              (when (or base q)
                (htm
                  (:span :style "float: right;" (:a :href (str base-url)
                                                          (str (s+"show all " type "s")))))))
            (iter (for i from 0 to (+ start 20))
                  (cond
  