anchor.diff:         (slot-value slotd 'reader-function)
          #'(lambda (object)
   	   (declare (ignore object))
  -	   (error "Can't read slot: ~A" (slot-definition-name slotd)))
  +	   (error "Slot is not readable: ~A" (slot-definition-name slotd)))
          (slot-value slotd 'boundp-function)
          #'(lambda (object) (declare (ignore object)) nil))
   
  
positive.code: 	(format stream "at 0x~X" (sap-int (foreign-location instance)))
        (write-string "at \"unbound\"" stream))))
  
  (defmethod initialize-instance :around ((instance proxy) &rest initargs)
    (declare (ignore initargs))
    (prog1
        (call-next-method)
      (cache-instance instance)
  
negative.code:   (setf 
     (slot-value slotd 'writer-function)
     (if (not (slot-boundp slotd 'setter))
         #'(lambda (value object)
  	   (declare (ignore value object))
  	   (error "Slot is not writable: ~A" (slot-definition-name slotd)))
       (with-slots (setter) slotd
         (etypecase setter
  	 (function setter)
  