anchor.diff:  (define-presentation-method presentation-typep (object (type character))
     (characterp object))
   
  +(defmethod presentation-type-of ((object character))
  +  'character)
  +
  +(define-presentation-method present (object (type character) stream
  +				     (view textual-view)
  +				     &key acceptably for-context-type)
  +  (declare (ignore acceptably for-context-type))
  +  (princ object stream))
  +
   (define-presentation-type string (&optional length))
   
   (define-presentation-method presentation-typep (object (type string))
  
positive.code: 	   (<= low object))
         (or (eq high *)
  	   (<= object high))))
  
  ;;; Define a method that will do the comparision for all real types.  It's
  ;;; already determined that that the numeric class of type is a subtype of
  
negative.code:        (or (eq high '*)
  	   (<= object high))))
  
  (defmethod presentation-type-of ((object rational))
    'rational)
  
  (define-presentation-method present (object (type rational) stream
  				     (view textual-view)
  				     &key acceptably for-context-type)
    (declare (ignore acceptably for-context-type))
    (let ((*print-base* base)
  	(*print-radix* radix))
      (princ object stream)))
  
  (define-presentation-type integer (&optional low high)
    :options ((base 10) radix)
    :inherit-from `((rational ,low ,high) :base ,base :radix ,radix))
  