anchor.diff:  
   (defmethod idltype-tc ((self Value-Def))
     (create-value-tc (op:id self) (op:name self) 
  -                   (cond ((omg.org/features:is_abstract self) omg.org/corba:vm_abstract)
  -                         ((omg.org/features:is_custom self) omg.org/corba:vm_custom)
  -                         ((omg.org/features:is_truncatable self) omg.org/corba:vm_truncatable)
  -                         (t omg.org/corba:vm_none))
  -                   (omg.org/features:base_value self)
  +                   (cond ((op:is_abstract self) corba:vm_abstract)
  +                         ((op:is_custom self) corba:vm_custom)
  +                         ((op:is_truncatable self) corba:vm_truncatable)
  +                         (t corba:vm_none))
  +                   (op:base_value self)
                      (simple-value-members
  -                    (omg.org/features:contents self :dk_valuemember t))))
  +                    (op:contents self :dk_valuemember t))))
   
   (define-method contents ((obj Value-Def) limit-type exclude-inherit)
     (if exclude-inherit
         (call-next-method)
  -    (append (call-next-method)
  -            (and (op:base_value obj)
  +    (append (and (op:base_value obj)
                    (op:contents (op:base_value obj) limit-type nil))
  +            (call-next-method)
               (loop for x in (coerce (op:abstract_base_values obj) 'list)
                   append (op:contents x limit-type nil))
               (loop for x in (coerce (op:supported_interfaces obj) 'list)
  
positive.code:    ;; boolean is_truncatable
     :is_truncatable (op:is_truncatable def)
     ;; RepositoryId base_value
     :base_value (op:id (op:base_value def))
     ;; TypeCode type
     :type (op:type def)))
  
  
negative.code:                (every (lambda (x) (typep x 'CORBA:UnionMember))
                        members))
            (members)
            'type-error :datum 'members :expected-type 'corba:unionmemberseq)
    (addto self (make-instance 'union-def
                  :id id :name name :version version
                  :discriminator_type_def discriminator_type
  