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Re: worries about useMentionOp and how queries relate to rules and proofs

From: <jos.deroo@agfa.com>
Date: Sun, 6 Feb 2005 01:07:29 +0100
To: phayes@ihmc.us
Cc: Dan Connolly <connolly@w3.org>, "Eric Prud'hommeaux" <eric@w3.org>, www-archive@w3.org
Message-ID: <OFF87D917F.910B3ED0-ONC1256F9F.00822966-C1256FA0.0000AE63@agfa.com>

>> I was a good boy and tried out the XSLT approach. Praise and cash
>> donations cheerfully accepted.
>
> Sheesh, I'm impressed. By you, that is, not by XSLT. D3 >> B2, I'd say.
>
> More I think about this, more I like the idea of allowing these 
> thingies, but putting them in a the query in a place where they 
> really are forced to be on a special stage, as it were. How about 
> something like an explicit 'filter' construct, so we might have
>
>> SELECT ?annot ?author
>>                WHERE { (?annot dc:creator ?author)
>>                                (?annot dc:created ?when) }
>>                  FILTER ( isURI(?author) ||
>                                 ?when < xs:dateTime(20050101T00:00:00Z) 
)
>
> The point being that 'AND' reads altogether to much like a 
> conjunction, as though you were just tacking an extra piece on to the 
> RDF pattern in the WHERE; whereas this lets us have warnings like 
> "filters cannot be represented in RDF"
>
> Dan & Jos, would this make you any happier?

Hm.. thinking about the subject of this thread
"..how queries relate to rules and proofs"
I think a query is like a filter rule
{WHERE-triples} => {SELECT-triples}
actually fitting nicely with sequent proofs
and I don't see how that syntactic FILTER
evidence fits with rest of proof, so I really
would keep it in the I/O of the proof engines
(but of course the stuff from AND clause such as e.g.
?X math:lessThan 30 I would put in the WHERE-triples)

-- 
Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
Received on Sunday, 6 February 2005 00:08:27 GMT

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