anchor.diff:  
   (defmethod finalize ((instance namespace-registry))
     ;; FIXME: call FINALIZE sometime after model initialization
  -  ;;
  -  ;; FIXME: how to make the instance's slot values read-only ?
  -  ;;        ^ (needs CLOS, SLOT-VALUE-USING-CLASS, etc
  -
  -  ; FIXME: Thread safety
  +  ;; FIXME: Thread safety
     (let ((table (coerce (namespace-registry-namespace-table instance)
   		       'simple-vector)))
       (setf (namespace-registry-namespace-table instance)
   	  table)
       (do-vector (ns (the simple-vector table) instance)
  -      (finalize ns)
  -      )))
  -
  -#+NIL
  +      (finalize ns))))
  +
  +
   (defmethod unfinalize ((instance namespace-registry))
  -  (setf (namespace-registry-namespace-table instance)
  -	...))
  +  ;; Assumption: INSTANCE is finalized
  +  ;; FIXME: Thread Safety
  +  ;; FIXME: Regression testing
  +  (let* ((table (namespace-registry-namespace-table instance))
  +	 (len (length (the simple-vector table))))
  +    (setf (namespace-registry-namespace-table instance)
  +	  (make-array len
  +		      :element-type 'namespace
  +		      :fill-pointer len
  +		      :adjustable t
  +		      :initial-contents table))
  +    (do-vector (ns (the simple-vector table) instance)
  +      (unfinalize ns))))
  +
   
   ;;; * Condition Types NAME-CONDITION, NAMESPACE-CONDITION
   
  
positive.code: 
  ;;; ** Meta Registry (Multiple Namespaces)
  
  (defstruct (namespace-registry
  	    (:include finalizable-instance)
  	    (:constructor make-namespace-registry ())
  
negative.code: 
  (defmethod finalize ((instance namespace))
    ;; FIXME: call FINALIZE sometime after model initialization
    ;; FIXME: Thread safety
    (setf (namespace-prefix-table instance)
  	(coerce (namespace-prefix-table instance)
  		'simple-vector)))
  
  
  (defmethod unfinalize ((instance namespace))
    ;; Assumption: INSTANCE is finalized
    ;; FIXME: Regression testing
    ;; FIXME: Thread safety
    (let* ((table (namespace-prefix-table instance))
  	 (len (length (the simple-vector table))))
      (setf (namespace-prefix-table instance)
  	  (make-array len
  		      :element-type 'simple-string
  		      :fill-pointer len
  		      :adjustable t
  		      :initial-contents table))))
  
  
  (declaim (type hash-table *qname-ns-registry*))
  
  