anchor.diff:    `(progn
        (defmethod ,(intern (modf-name name) :modf) (,new-val ,@args)
          ,@body )
  -     (setf (gethash ',name *modf-nth-arg*)
  -           ,nth-arg )))
  +     (eval-when (:compile-toplevel :load-toplevel :execute)
  +       (setf (gethash ',name *modf-nth-arg*)
  +             ,nth-arg ))))
   
   ;; @\section{The {\em modf} macro}
   
  
positive.code:   "Define a new rewrite rule.  If a form starting with NAME is encountered, call
  the defined function to return a form that we can deal with (i.e. one defined
  via DEFINE-MODF-EXPANDER, DEFINE-MODF-FUNCTION, and DEFINE-MODF-METHOD)."
    `(setf (gethash ',name *modf-rewrites*)
           (lambda (,expr)
              ,@body )))
  
  ;; @\section{Defining Modf functions and methods}
  
  
negative.code:   `(progn
       (defun ,(intern (modf-name name) :modf) (,new-val ,@args)
         ,@body )
       (eval-when (:compile-toplevel :load-toplevel :execute)
         (setf (gethash ',name *modf-nth-arg*)
               ,nth-arg ))))
  
  ;; <<>>=
  (defmacro define-modf-method (name nth-arg (new-val &rest args) &body body)
  