anchor.diff:  
   (defsingleton singleton-2-2 (singleton-1-1)
     ((sl-c)))
  -
  +;; FIXME [CCL] - LOOP (??)
   
   (class-slots (find-class 'singleton-2-2))
   
  
positive.code:              ;; NB: This implementation, in effect, prevents any usage
               ;; of forward-referenced classes in the SUPERCLASSES list
  
               (defclass ,%proto-name (,@user-metaclass prototype-class
                                                        ,@superclasses)
                 ;; NB: See also, the FIXME remark in the definition of
  
negative.code:     ;; [SBCL]
      ;;
      (defparameter *the-s*
        (make-instance s :name (gentemp "S-")
                       :prototype-class (gensym "S-PROTO-")
                       :direct-superclasses (list s)
                       ;; :ensure-prototype t ;; this obviates the previous remarks
  