W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > June 2002

Re: Dark triples, current closure / entailment rules, can someone clarify?

From: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
Date: Wed, 26 Jun 2002 09:17:00 +0100
Message-Id: <>
To: pat hayes <phayes@ai.uwf.edu>
Cc: w3c-rdfcore-wg@w3.org


I get very nervous if we feel that we have to be responsible for every way 
that users might mis-use our specifications.  Without doubt, if it gains 
any kind of widespread currency the Semantic Web will contain faulty 
reasoners, and we'll have to learn to cope with them (e.g. having some 
framework --possibly localized-- for deciding what to trust).  The points 
you make seem to me to be no more or less than faulty reasoners.


At 06:58 PM 6/25/02 -0500, pat hayes wrote:
>>At 10:19 AM 6/25/02 -0500, pat hayes wrote:
>>>I fail to follow why this kind of example would lead you to that 
>>>conclusion. BUt in any case there are other strong reasons for not 
>>>coming to that conclusion, which we have gone over now several times. If 
>>>there is any way to assert darkness, then there is no way, in practice, 
>>>to avoid nonmonotonicity. ...
>>You say _no_ way, but I thought that a syntax extension (in the graph 
>>syntax) was a possibility.
>Well, what I meant by _no_ was that if there is any way at all of 
>asserting it, then someone somewhere is going to hack a way of not 
>asserting it, and then someone else is going to find a way to add it, and 
>I guess I have great respect for the creativity of users to find a way to 
>break almost any spec that is breakable. For evidence, read the recent 
>thread on RDF logic about how to provide urirefs for graph arcs. For more 
>evidence, consider the fact that the Stanford DAML reasoning engine has an 
>(illegal, but..) 'unassert' command built into it.
>>I agree it has the other disadvantages you mention, but I want to be 
>>clear what our *possible* choices are.
>Well, I guess it depends on how cynical you are :-)
>IHMC                                    (850)434 8903   home
>40 South Alcaniz St.                    (850)202 4416   office
>Pensacola,  FL 32501                    (850)202 4440   fax
>phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes

Graham Klyne
Received on Wednesday, 26 June 2002 04:15:43 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 20:24:13 UTC