anchor.diff:            (pov-integer-vector-y object)
             (pov-integer-vector-z object)))
   
  +(defmethod object-rope ((object pov-integer-vector))
  +  (rope '|<|
  +        (int-string (pov-integer-vector-x object)) '|, |
  +        (int-string (pov-integer-vector-y object)) '|, |
  +        (int-string (pov-integer-vector-z object)) '|>|))
  +
   (defstruct (pov-value (:constructor pov-value (value)))
     value)
   
  
positive.code:             (pov-block-name object)
              (pov-block-list object)
              old-indent)))
  
  (defstruct (pov-list (:constructor %pov-list (name list length)))
    name
  
negative.code: (defmacro with-pov-indent (old-indent &body body)
    `(let* ((,old-indent *pov-indent*)
            (*pov-indent* (make-string (+ *pov-indent-width* (length *pov-indent*))
                                       :initial-element #\Space))
            (*pov-newline-indent* (let ((tmp (make-string (+ 1 *pov-indent-width* (length *pov-indent*))
                                                          :initial-element #\Space)))
                                    (setf (schar tmp 0) #\Newline)
                                    tmp)))
       ,@body))
  
  ;; (defmacro with-pov-block (output &body body)
  