anchor.diff:  		       (write-vint freq 0)
   		       (write-vint freq posting-freq)))
   		 (let ((last-position 0))
  -		   (dolist (position (positions posting))
  +		   (dosequence (position (positions posting))
   		     (write-vint prox (- position last-position))
   		     (setf last-position position)))
  -		 (let ((term-field (field (term posting))))
  +		 (let ((term-field (term-field (term posting))))
   		   (when (not (equal current-field term-field))
   		     (setf current-field term-field)
   		     (let ((fi (get-field field-infos current-field)))
  
positive.code: 				   (progn
  				     (add-position self
  						   field-name
  						   (token-text token)
  						   position
  						   (make-instance 'term-vector-offset-info
  								  :start-offset (+ offset (token-start token))
  
negative.code: 	  (tv-writer nil))
        (unwind-protect
  	   (let ((tis-writer (make-instance 'term-infos-writer
  					    :dir directory
  					    :segment segment
  					    :field-infos field-infos
  					    :interval term-index-interval))
  		 (ti (make-instance 'term-info))
  		 (current-field nil))
  	     (setf freq (open-segment-file directory segment *frq-extension* :output))
  	     (setf prox (open-segment-file directory segment *prx-extension* :output))
  	     (dosequence (posting postings)
  	       (set-values ti 1 (pos freq) (pos prox) -1)
  	       (add-term tis-writer (term posting) ti)
  	       (let ((posting-freq (freq posting)))
  