self.slot->select(sl : SlotType1 |
	(not sl.name.oclIsUndefined()) and 
	sl.name='repositoryUniqueId'
)->forAll(sl : SlotType1 |
	sl.valueList.oclIsUndefined() or 
	sl.valueList.value->size()=0 or 
	(
		sl.valueList.value->size()=1 and 
		self.isOID(sl.valueList.value->first())
	)
)