anchor.diff:  
   (defvar *kill-new-flag* t)
   (defvar *kill-before-p* nil)
  -(defvar *kill-disable-p* nil)
   
   (defun kill-append (lines before-p)
     (setf (car *kill-ring*)
  
positive.code:         (kill-ring-nth n)))
  
  (defmacro with-kill (() &body body)
    `(unless *kill-disable-p*
       (when-interrupted-flag :kill
                              (setq *kill-new-flag* t))
       ,@body))
  
negative.code:           *kill-ring-max*
            *kill-new-flag*
            *kill-before-p*
            kill-append
            kill-push
            yank
  