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Re: Requirements for a possible "RDF 2.0"

From: Danny Ayers <danny.ayers@gmail.com>
Date: Fri, 15 Jan 2010 21:20:21 +0100
Message-ID: <1f2ed5cd1001151220x64b52058n233bde5869b8bab9@mail.gmail.com>
To: Toby Inkster <tai@g5n.co.uk>
Cc: jeremy@topquadrant.com, "semantic-web@w3.org" <semantic-web@w3.org>
Thanks Toby, that's compelling enough for me.

2010/1/15 Toby Inkster <tai@g5n.co.uk>:
> On Fri, 2010-01-15 at 11:57 +0100, Danny Ayers wrote:
>> Aside from a little  tidiness, what would we actually gain through
>> going the whole hog on what can go in which position in the triple?
>>
>> blank node predicate - what does that tell you that an rdfs:seeAlso
>> wouldn't?
>
> <#school>
>  [
>    rdfs:subPropertyOf ex:teacher ;
>    rdfs:label "maths teacher" ;
>    ex:relatedTopic dbpedia:Mathematics
>  ]
>    <#joe> .
>
> <#band>
>  [ rdfs:subPropertyOf foaf:member ; ex:relatedInstrument <#bongo> ]
>    <#jim> .
>
> These structures are of course already permissible in RDF, but only if
> you're willing to commit to giving the property a URI.
>
>> literal subject - aside from quotations:
>>
>> "I can't really see how it would be useful" <x:saidBy> <#me> .
>
> If the above was the only use case, then it would not be especially
> useful - you'd simply create a x:didSay predicate that worked in the
> reverse direction. With blank node predicates that's even easier:
>
>  <#me>
>    [ owl:inverseOf x:saidBy ]
>      "I can't really see how it would be useful" .
>
> But that's not the only use case. Consider relationships between two
> literals:
>
>  "Toby Inkster" foaf:sha1 "4296ab2b2243bdb1e3cd1952158d2ce5464ea10c" .
>
> I can imagine wanting to do things like:
>
>  SELECT ?person ?hash
>  WHERE {
>    ?person ex:password ?pwd .
>    ?pwd foaf:sha1 ?hash .
>    FILTER (?hash = "672059bd1419f8b90633fc2d02529be0de2fa614")
>  }
>
> Both blank node predicates and literal subjects are already allowed by
> N3 and are theoretically allowed by SPARQL (though I don't know of any
> implementations that choose to support them).
>
> --
> Toby A Inkster
> <mailto:mail@tobyinkster.co.uk>
> <http://tobyinkster.co.uk>
>
>



-- 
http://danny.ayers.name
Received on Friday, 15 January 2010 20:20:56 UTC

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