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