anchor.diff:                 #+lispworks `(hcl::slot-definition-initargs ,slot)
                  #+lucid `(clos:slot-definition-initargs ,slot)
                  #+sbcl `(slot-value ,slot 'sb-pcl::initargs)
  -               #+ccl `(ccl:slot-definition-initargs ,slot)
  -               #+abcl `(mop::slot-definition-initargs ,slot))
  +               #+ccl `(ccl:slot-definition-initargs ,slot))
                (slot-one-initarg (slot) `(car (slot-initargs ,slot)))
                (slot-alloc (slot)
                  #+(and allegro (not (version>= 6)))
  
positive.code:                #+lispworks `(hcl::class-slots ,class)
                 #+lucid `(clos:class-slots ,class)
                 #+sbcl `(sb-pcl::class-slots ,class)
                 #+ccl `(ccl:class-slots ,class)
                 #+abcl `(mop:class-slots ,class))
               (class-slots1 (obj)
                 `(class-slots*
                   (typecase ,obj
  
negative.code:                #+lispworks `(hcl::slot-definition-allocation ,slot)
                 #+lucid `(clos:slot-definition-allocation ,slot)
                 #+sbcl `(sb-pcl::slot-definition-allocation ,slot)
                 #+ccl `(ccl:slot-definition-allocation ,slot)))
  
      #+abcl (progn
               (defmacro class-slots* (class)
                 `(mop:class-slots ,class))
               (defmacro class-slots1 (obj)
                 `(class-slots*
                   (typecase ,obj
                     (class ,obj)
                     (symbol (find-class ,obj))
                     (t (class-of ,obj)))))
               (defmacro slot-name (slot)
                 `(mop:slot-definition-name ,slot)) 
               (defmacro slot-initargs (slot)
                 `(mop::slot-definition-initargs ,slot)) ; xxx
               (defmacro slot-one-initarg (slot)
                 `(car (slot-initargs ,slot)))
               (defmacro slot-alloc (slot)
                 `(mop::slot-definition-allocation ,slot))) ; xxx
  
      (defun class-slot-list (class &optional (all t))
        "Return the list of slots of a CLASS.
  