anchor.diff:  	(setf deleted-docs (read-bit-vector directory (add-file-extension segment "del"))))
         (setf freq-stream (open-segment-file dir segment "frq" :input))
         (setf prox-stream (open-segment-file dir segment "prx" :input))
  -      (setf norms '())
         (setf norms-dirty-p NIL)
         (open-norms self dir)
         (setf tv-reader-orig NIL)
  
positive.code:    (term-infos)
     (freq-stream)
     (prox-stream)
     (norms)
     (norms-dirty-p)
     (tv-reader-orig))
  )
  
negative.code: 	       (file-exists-p directory (add-file-extension segment "del")))
        (delete-file directory (add-file-extension segment "del")))
      (when norms-dirty-p
        (loop for norm being the hash-values in norms
  	 do (when (dirty-p norm)
  	      (re-write norm directory segment (max-doc self) cfs-reader))))
      (setf deleted-docs-dirty-p NIL
  	  norms-dirty-p NIL
  	  undelete-all-p NIL)))
  