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Re: skolems: visible differences?

From: Bijan Parsia <bparsia@cs.man.ac.uk>
Date: Sun, 13 Jan 2008 00:09:43 +0000
Message-Id: <9F71296B-D831-462E-A9DB-41B6D32ADFC2@cs.man.ac.uk>
To: OWL Working Group WG <public-owl-wg@w3.org>

On Jan 12, 2008, at 11:52 PM, Alan Ruttenberg wrote:

> Testing my understanding of the skolem constant proposal for  
> anonymous individuals:
>
> If we adopted the treatment of bnodes as skolem constants, would it  
> be the case that we no longer had the tree-shape restriction for  
> related anonymous individuals?

Correct. You could still get them, but you would have to encode them  
as existential restrictions, or using Carsten's proposed universal role.

> If that is the case, could we simply have the syntax allow turtle  
> style bnode syntax _:xxx for individual names and have these be  
> considered anonymous individuals in the way RDF people are used to  
> writing them?

Yep.

> As I understood it, the avoidance of giving names to anonymous  
> individuals was to make it impossible to express, in the abstract  
> syntax, anything but tree-shape relationships.

Yep. They become names that have certain conditions on parsing,  
serialization, and merging.

> Coupling this with serializing skolem constants as bnodes, it would  
> seem that this would advance our ability to have more RDF graphs be  
> considered valid OWL, affirmatively addressing Issue 46, yes?

Yep. It also makes SPARQL/OWL work much much better (i.e., more  
compatibly with SPARQL/RDF).

Cheers,
Bijan.
Received on Sunday, 13 January 2008 00:10:01 GMT

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