anchor.diff:  
   (defmethod object-rope ((object pov-rgb))
     (rope '|rgb<|
  -        (float-string (pov-rgb-r object)) '|, |
  -        (float-string (pov-rgb-g object)) '|, |
  -        (float-string (pov-rgb-b object))
  +        (pov-rgb-r object) '|, |
  +        (pov-rgb-g object) '|, |
  +        (pov-rgb-b object)
           '|>|))
   
   (defstruct (pov-rgbf (:constructor %pov-rgbf (r g b f)))
  
positive.code: (defmethod object-rope ((object pov-item))
    (rope (pov-item-name object)
          '| |
          (object-rope (pov-item-value object))))
  
  (defstruct (pov-rgb (:constructor %pov-rgb (r g b)))
    "Type for a povray RGB color."
  
negative.code: 
  (defmethod object-rope ((object pov-float-vector))
    (rope '|<|
          (pov-float-vector-x object) '|, |
          (pov-float-vector-y object) '|, |
          (pov-float-vector-z object) '|>|))
  
  (defstruct (pov-integer-vector (:constructor %pov-integer-vector (x y z)))
    "Type for a povray vector."
  