W3C home > Mailing lists > Public > semantic-web@w3.org > August 2006

Re: Reifying triples as unique URIs

From: Damian Steer <damian.steer@hp.com>
Date: Mon, 07 Aug 2006 16:59:21 +0100
Message-ID: <44D76359.5010406@hp.com>
To: Max Völkel <voelkel@fzi.de>
CC: semantic-web <semantic-web@w3.org>

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Max Völkel wrote:

> Version 3)
> ---------
> Unique Relations
> 
> This  is  a  new idea, that I haven't seen discussed anywhere - that's
> why  I post this email. The idea is: In some way, the relation between
> two things is unique. So we represent
> (a,b,c)
> as (a,x,c), (x rdfs:subPropertyOf b).
> We  use  b  as  the  type of the relation, x is a random unique URI (I
> don't like blank nodes).

Despite the fact that they seem ideal for this case :-)

> What  do  you think about the idea to reify triples as unique property
> URIs? Has this been discussed elsewhere?
> 
> 
> Kind regards,
> 
>   Max Völkel

This was certainly suggested as an option for foaf chat ids a few years
ago, but I can't find the discussion.

The issue was that there are many systems where one might have an
account, and having to create a property for each (such as
foaf:icqChatID) seems like it could have problems in the long run. If we
could qualify foaf:nick, mentioning the system the nick is for, then
that seems a better solution.

Of course you can't qualify properties, but the bnode property trick was
a suggestion.

_:damian _:nick "pldms" .
_:nick rdfs:subPropertyOf foaf:nick ;
	ex:onSystem <...icq...> .

Try writing that in RDF/XML :-)

Now we have foaf:OnlineAccount, which achieves a similar thing.

_:damian foaf:holdsAccount [ foaf:accountName "pldms" ; 			
foaf:accountServiceHomepage <...icq...> ] .

This is really the n-ary relation modelling problem, and could have done
something like:

[] ex:holder _:damian ; ex:nick "pldms" ; ex:system <...icq...> .

You might want to look at [1] about this.

Damian

[1] <http://www.w3.org/TR/swbp-n-aryRelations/>
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Received on Monday, 7 August 2006 15:59:38 UTC

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