anchor.diff:  
   (parse-bibtex-name-list '())
   
  -|#
  +||#
  
positive.code: 
  (defun mark-history (level)
    (cond ((> level *history*)
  	 (setq *history* level))
  	((= level *history*)
  	 (incf *err-count*))))
  
  
negative.code:       (bib-error "Expected `~A' sign" close-char))))
  
  (defun process-bib-preamble-command ()
    (let* ((open-char (peek-char t *bib-stream*))
  	 (close-char
  	  (case open-char
  	    (#\{ #\})
  	    (#\( #\))
  	    (otherwise "Expected a `(' or `{' sign"))))
      (read-char *bib-stream*)
      (setf *bib-preamble*
  	  (concatenate 'string *bib-preamble* 
  		       (read-bib-field-value nil)))
      (unless (char= (peek-char t *bib-stream*)
  		   close-char)
        (bib-error "Expected `~A' sign" close-char))))
  
  
  (defun make-bib-entry ()
    (make-hash-table :size 16 :test 'equalp))
  
  (defun process-bib-entry-command (entry-type)
    (let* ((open-char (peek-char t *bib-stream*))
  