anchor.diff:     (%direct-slots 
       :initarg :direct-slots
       :reader class-direct-slots
  -    ;; Additional reader; see remark above.
  -    :reader direct-slots
       :writer (setf c-direct-slots))
      (%direct-superclasses 
       ;; This slot has no initform and no initarg, because it is set by
  
positive.code: ;;; STANDARD-CLASS.
  ;;;
  ;;; Some slots have an additional reader (in addition to the one
  ;;; stipulated by the AMOP), because we want FINALIZE-INHERITANCE-AUX
  ;;; to work on built-in classes as well as on standard classes.  And
  ;;; FINALIZE-INHERITANCE-AUX needs to access slots both in standard
  ;;; classes and built-in classes.  But the AMOP requires that the
  ;;; specified readers return the empty list for built-in classes.  The
  ;;; solution is to use an additional set of readers that do not appear
  ;;; in the specification, and that work both for built-in and for
  ;;; standard classes.
  
  ;;; FIXME: it looks like some code factoring would be useful here.
  (defclass standard-class (class)
  
negative.code:    (%effective-slots 
      :initform '() 
      :reader class-slots
      :writer (setf c-slots))
     (%prototype
      :reader class-prototype
  