anchor.diff:  				     stream
   				     (view textual-view)
   				     &key acceptably for-context-type)
  -  (declare (ignore acceptably for-context-type))
  +  (declare (ignore object acceptably for-context-type))
     (write-string "None" stream))
   
   (define-presentation-type boolean ())
  
positive.code:   
  (defmacro define-subtypep-method (&rest args)
    (let ((gf (gethash 'presentation-subtypep *presentation-gf-table*)))
      (multiple-value-bind (qualifiers lambda-list body)
  	(parse-method-body args)
        (let ((type-arg (nth (1- (type-arg-position gf)) lambda-list)))
  	
  
negative.code: 				   &optional
  				   (stream *standard-output*)
  				   (plural-count 1))
    (flet ((describe-it (stream)
  	   (funcall-presentation-generic-function describe-presentation-type
  						  type
  						  stream
  						  plural-count)))
      (if stream
  	(describe-it stream)
  	(with-output-to-string (s)
  	  (describe-it s)))))
  
  ;;; Views...
  
  