anchor.diff:    ())
   
   
  -(defmethod effective-slot-definition-class ((class singleton-class)
  +(defmethod effective-slot-definition-class ((class singleton)
                                               &rest initargs)
     (find-class 'singleton-effective-slot-definition))
   
  
positive.code: (defclass singleton-1 ()
    ((sl-a)
     (sl-b))
    (:metaclass singleton-class))
  
  (finalize-inheritance (find-class 'singleton-1))
  
  
negative.code: 
  
  
  (defclass singleton (standard-class)
    ())
  
  
  (validate-class singleton)
  
  
  (defclass singleton-slot-definition (standard-slot-definition)
  