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Re: [RDF-CONCEPTS] Skolemization

From: Andy Seaborne <andy@apache.org>
Date: Mon, 17 Jun 2013 10:36:45 +0100
Message-ID: <51BED8AD.8000609@apache.org>
To: public-rdf-comments@w3.org
On 17/06/13 10:22, Markus Lanthaler wrote:
> On Monday, June 17, 2013 10:37 AM, Andy Seaborne wrote:
>> There seem to be 3 kinds of skolemization:
>>
>> 1/ replacement (unconstrained; one-way)
>>
>> 2/ round-trippable (the generating system can recover a bNode if the
>> URI comes back; this was one of the original motivations)
>
> I think the key point here is that it is done within the boundaries of a
> single system you have control over.
>
>
>> 3/ globalization (giving a recognizable identify to the bnode outside
>> it's original context/data; the bnode is now transferrable to other
>> systems; other systems can reverse the process)
>
> Wouldn't that mean that a Skolem IRI === bNode and thus be at odds with the
> definition of bnodes: "The blank nodes in an RDF graph are drawn from an
> infinite set. This set is disjoint from the set of all IRIs and the set of
> all literals".

It's giving a name so it's not identity.  It's not happening at the 
level of semantics or the proper data model. You can think of it as a It 
is extending 2 to create a tunnel for blank nodes within the RDF 1.1 
syntax.  The fact that the rules for skolemization are now published (in 
2, they are not) makes it different.

	Andy

>
>
> --
> Markus Lanthaler
> @markuslanthaler
>
>
Received on Monday, 17 June 2013 09:37:18 UTC

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