anchor.diff:                                   (slot-def (accessor-method-slot-definition (first applicable-methods)))
                                    (slot-name (slot-definition-name slot-def))
                                    (effective-slot (find-effective-slot instance slot-name)))
  -                            (register-redefinition-flusher gf class)
                               (cond (effective-slot
                                      (let ((location (safe-slot-definition-location effective-slot)))
                                        (lambda (object)
  
positive.code:                                  (slot-def (accessor-method-slot-definition (first applicable-methods)))
                                   (slot-name (slot-definition-name slot-def))
                                   (effective-slot (find-effective-slot instance slot-name)))
                              (register-redefinition-flusher gf class)
                              (cond (effective-slot
                                     (let* ((location (safe-slot-definition-location effective-slot))
                                            (typecheck (safe-slot-definition-typecheck effective-slot))
  
negative.code:                        (std-compute-effective-method-function gf applicable-methods)
                         (compute-effective-method-function gf applicable-methods))))
          (insert-into-emf-cache (classes-to-emf-table gf) args emfun)
          (dolist (c classes)
            (register-redefinition-flusher gf c))
          (apply emfun args)))))
  
  (defun reordered-argument (gf arguments index)
  