anchor.diff:  	(toplevel-count   0)
   	(toplevel-rule  (parser-toplevel-rule (parse-session-parser session)))
   	(locations      (parse-session-locations session))
  -	(reported-gap?  nil))
  +	;; (reported-gap?  nil)
  +	)
       (dolist (node (parser-location-post-nodes loc))
         (let ((post-index (parser-node-post-index node)))
   	(cond ((> post-index max-index)
  
positive.code:     (when (> max-index (+ pre-index min-size))
        ;;
        (unless (= prior-post-index pre-index) 
  	(when (report-gap session prior-post-index pre-index)
  	  (setq reported-gap? t)))
        (setq prior-post-index max-index)
        ;;
        (let ((alternative-results nil))
  
negative.code: 	    (report-ambiguity session pre-index max-index alternative-results)))
  	(setf (parse-session-results session)
  	  (append alternative-results (parse-session-results session)))))
      (values max-index prior-post-index))) ;  reported-gap?
  
  (defun report-gap (session start end)
    (let ((locations (parse-session-locations session))
  