anchor.diff:  		     (and (null (set-exclusive-or
   				 (method-qualifiers method)
   				 (method-qualifiers existing-method)))
  -			  (equal (m-specializers method)
  -				 (m-specializers existing-method))))
  +			  (equal (method-specializers method)
  +				 (method-specializers existing-method))))
   		   (gf-methods generic-function))))
       (unless (null method-to-remove)
         (remove-method generic-function method-to-remove)))
  
positive.code:   ;; Associate GENERIC-FUNCTION with METHOD.
    (setf (m-generic-function method) generic-function)
    ;; Call ADD-DIRECT-METHOD for each of the specializers of METHOD.
    (loop for specializer in (m-specializers method)
  	do (add-direct-method specializer method))
    ;; Call COMPUTE-DISCRIMINATING-FUNCTION and install its result
    ;; with SET-FUNCALLABLE-INSTANCE-FUNCTION. 
  
negative.code:   (setf (gf-methods generic-function)
  	(remove method (gf-methods generic-function)))
    ;; Call REMOVE-DIRECT-METHOD for each of the specializers of METHOD.
    (loop for specializer in (method-specializers method)
  	do (remove-direct-method specializer method))
    ;; Disassociate GENERIC-FUNCTION from METHOD.
    (setf (m-generic-function method) nil)
  