W3C home > Mailing lists > Public > public-rdf-dawg-comments@w3.org > December 2006

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

From: Bob MacGregor <bmacgregor@siderean.com>
Date: Tue, 12 Dec 2006 11:18:05 -0800
To: "Pat Hayes" <phayes@ihmc.us> , "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>
Message-ID: <20061212111805048.00000005004@bmacgregor1>

Hi Pat,

I quoted you (see below) and now you have said that you have changed your mind.  However,
I found the quote by following Eric P's pointer back to the W3C document that buttressed the argument for closing the UNSAID issue.  If that quotation is not current, then I would recommend deleting it from the W3C document, or adding commentary noting the disagreement.  Right now, we have it on record that "God doesn't condone UNSAID", which basically kills the issue.

Am I correct that OPTIONAL/UNBOUND cannot simulate UNSAIDs containing a compound argument
(and hence that an "unrestricted UNSAID" is not a "convenience syntax")?

Cheers, Bob

>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 19:29:15 GMT

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