anchor.diff:  				   super-sequence super-test super-value-key)
   		t)))))
   
  +(define-presentation-method present (object (type completion) stream
  +				     (view textual-view)
  +				     &key acceptably for-context-type)
  +  (declare (ignore acceptably for-context-type))
  +  (present object (presentation-type-of object)
  +	   :stream stream :view view))
  +
   (define-presentation-type-abbreviation member (&rest elements)
     (make-presentation-type-specifier `(completion ,elements)
   				    :name-key name-key
  
positive.code:        (typep (realpart object) type)
         (typep (imagpart object) type)))
  
  
  (define-presentation-type real (&optional low high) :options ((base 10) radix)
  			  :inherit-from 'number)
  
negative.code: (define-presentation-method presentation-typep (object (type t))
    t)
  
  (define-presentation-method present (object (type t)
  				     stream
  				     (view textual-view)
  				     &key acceptably for-context-type)
    (declare (ignore for-context-type))
    (let ((*print-readably* acceptably))
      (princ object stream)))
  
  (define-presentation-type nil ())
  
  (define-presentation-method presentation-typep (object (type nil))
  