RE: Blank Node Equality Question

> 2/ If two blank nodes are connected to identical nodes via identical
> predicates then can any inference made about the first also be made about
> the second?  In RDF and RDFS this is true.  In many stronger languages,
> including OWL, this is not true.   For example
>
> 	_:a rdf:type ex:Class .
> 	_:b rdf:type ex:Class .
>
> entails in OWL
>
> 	_:a owl:sameAs _:a .
>
> but not
>
> 	_:a owl:sameAs _:b .
>

Completely exchanging _:a for _:b (and vice versa) will always provide a
proof for statements about _:b that are similar to proven statements about
_:a, so that

 _:b owl:sameAs _:b .

follows with a proof identical to that for

  _:a owl:sameAs _:a .

Jeremy

Received on Monday, 21 July 2003 06:08:34 UTC