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Re: Requirements for a possible "RDF 2.0"

From: Pat Hayes <phayes@ihmc.us>
Date: Fri, 15 Jan 2010 10:52:04 -0600
Cc: jeremy@topquadrant.com, tai@g5n.co.uk, "semantic-web@w3.org" <semantic-web@w3.org>
Message-Id: <E4C0D7F9-1FCF-451A-A52B-DF8EEA21ED05@ihmc.us>
To: Danny Ayers <danny.ayers@gmail.com>

On Jan 15, 2010, at 4:57 AM, Danny Ayers wrote:

> Jeremy, Toby, anyone,
>
>
> 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?

Well, the tidyness isnt to be sniffed at. It makes the specs a lot  
easier to write (and to read), for a start. Also it makes syntax  
checking easier. It makes it easier to think about the language (you  
don't have to keep mentally checking yourself to see if you've broken  
some arbitrary rule.) IT makes the closure inference rules and the  
query matching rules simpler and easier to implement. And it does no  
harm.

>
> blank node predicate - what does that tell you that an rdfs:seeAlso  
> wouldn't?

SeeAlso tells you almost nothing, in fact. But you could for example  
have a class of properties and say that one or more of them holds  
between two things. Consider for example

fatherOf rdf:type FamilyRelation .
motherOf rdf:type FamilyRelation .
sisterOf ... (etc.)

and then

_:x rdf:type FamilyRelation .
Alice _:x Bill .

says that Alice and Bill are related somehow. (In case you are  
thinking that subproperty would work here, it won't.)

>
> literal subject - aside from quotations:
>
> "I can't really see how it would be useful" <x:saidBy> <#me> .

"37"^^xsd:number rdf:type PrimeNumber .

"42"^^xsd:number :playsRoleIn  :HitchHIkersGuide .

"66"^^xsd:number :greaterThan _:x .
_:x :age :PatHayes .

(which is why I don't get a full SS pension this year).

I'm sure I could think of others.

But the main point is that allowing all this makes the language  
*simpler*. the question should be, why the hell did we not allow it in  
the first place?

Pat

>
> Cheers,
> Danny.
>
>

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Received on Friday, 15 January 2010 16:52:59 UTC

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