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Re: Prototype SPARQL engine based on Datalog and relation of SPARQL to the Rules Layer

From: Pat Hayes <phayes@ihmc.us>
Date: Tue, 12 Dec 2006 12:37:09 -0600
Message-Id: <p06230903c1a4a540986f@[10.100.0.128]>
To: Bijan Parsia <bparsia@cs.man.ac.uk>
Cc: "Eric Prud'hommeaux" <eric@w3.org>, "axel@polleres.net" <axel@polleres.net>, "public-rdf-dawg-comments@w3.org" <public-rdf-dawg-comments@w3.org>, "public-rdf-dawg@w3.org" <public-rdf-dawg@w3.org>, "Bob MacGregor" <bmacgregor@siderean.com>

>On Dec 7, 2006, at 5:07 PM, Bob MacGregor wrote:
>
>>I realize that the UNSAID issue is closed.  However, it shouldn't have been.
>
>I agree with this, but not for the reasons given below. As I pointed 
>out on behalf of Axel,
>
>>Here's what Pat Hayes said about it:
>>
>>
>>   If SPARQL contains UNSAID then it will be inconsistent with any
>>   account of meaning which is based on the RDF/RDFS/OWL normative
>>   semantics. This will not render SPARQL unusable, but it will place it
>>   outside the 'semantic web layer cake' and probably lead to the
>>   eventual construction of a different, and rival, query language for
>>   use by Web reasoners.
>
>Let me just interject that this argument does nothing for me.

For the record, it doesn't do much for me either. In fact, Ive 
changed my mind about this quite explicltly. Bob is referring to a 
VERY old conversation here. The only shred of this attitude I have 
left is that Id prefer to not say that UNSAID is NAF.

>I totally fail to see why having *convenience syntax* for 
>expressivity *already* in the language (via unbound) magically 
>breaks the architecture.

I agree.

>(Oh, and I'm unconvincable on this point, Pat, so please don't 
>bother :)) Generally, it's much easier and safer to shove funky 
>expressivity into query languages than it is to do so in the 
>representation formalism itself.

Again, I agree. I would prefer the query language to be almost totally funky.

Pat
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Received on Tuesday, 12 December 2006 18:37:21 GMT

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