anchor.diff:              #',(generic-function-name gf)
               ,(type-arg-position gf)
               ,@args)))
  -
   
   ;;; Used by map-over-presentation-type-supertypes as well
   
  
positive.code:                  (block ,name
                     ,@real-body)))))))))
  
  
  
  (defmacro define-default-presentation-method (name &rest args)
    (let ((gf (gethash name *presentation-gf-table*)))
      (unless gf
  
negative.code:                              :type-arg-position ,type-arg-pos)))
             (defgeneric ,generic-function-name ,gf-lambda-list
               (:generic-function-class presentation-generic-function)
               ,@options))))))
  
  (defun parse-method-body (args)
    (loop for arglist on args
  