anchor.diff:  
   
   
  -(defclass singleton-2 (singleton-1)
  -  ((sl-c))
  -  (:metaclass singleton))
  +(defsingleton singleton-2 (singleton-1)
  +  ((sl-c)))
   
   (finalize-inheritance (find-class 'singleton-2))
   
  
positive.code: #+nil
  (eval-when ()
  
  (defclass singleton-1 (singleton)
    ((sl-a)
     (sl-b))
    (:metaclass singleton))
  
  (finalize-inheritance (find-class 'singleton-1))
  
  
negative.code:   (:nicknames #:ltp.common.mop.singleton)
    (:use #:ltp/common/mop
          #:ltp/common
          #:cl)
    (:export
     #:singleton
     #:defsingleton
     ))
  
  (in-package #:ltp/common/mop/singleton)
  
  