Due to the size and rate of change on the Web, the
closed-world assumption (which states that anything that
cannot be inferred is assumed to be false) is inappropriate.
However, there are many situations where closed-world information
would be useful. Therefore, the language must be able to state that a given
ontology can be regarded as complete. This would then sanction additional
inferences to be drawn from that ontology. The precise semantics of such a
statement (and the corresponding set of inferences) remains to be defined,
but examples might include assuming complete property information about
individuals, assuming completeness of class-membership, and assuming
exhaustiveness of subclasses.
