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Re: Sloppy inference rules

From: Pat Hayes <phayes@ihmc.us>
Date: Wed, 7 Nov 2012 19:11:20 -0600
Cc: Ivan Herman <ivan@w3.org>, Guus Schreiber <guus.schreiber@vu.nl>, RDF WG <public-rdf-wg@w3.org>
Message-Id: <416CBE70-15B1-4A35-9D0E-2D15352868E8@ihmc.us>
To: Richard Cyganiak <richard@cyganiak.de>

On Nov 7, 2012, at 6:52 PM, Richard Cyganiak wrote:

> On 8 Nov 2012, at 00:22, Pat Hayes wrote:
>> _:x :a ex:Fish .
>> 
>> does not entail
>> 
>> skolem:newname2346 :a ex:Fish .
>> 
>> So any rules that go from a bnode-containing triple to another triple containing the same bnode can't work by going 'through' triples in which the bnode is replaced by a skolemized URI.
> 
> But can't this trivially be solved by saying, “assume a semantics where {_:x ?p ?o} entails {skolem:x ?p ?o} for any x and vice versa”?

Well, that is rather like saying that one can get out of debt by saying "assume I have more money". Remember "entails" has a fixed meaning: (A entails B) means that for every interpretation I, if I(A)=true then I(B)=true. If you can find a notion of interpretation which makes this work, then I'd be interested to see it. 

Pat

> 
> Best,
> Richard
> 
> 
> 
>> 
>> Pat
>> 
>> 
>> ------------------------------------------------------------
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>> 
>> 
>> 
>> 
>> 
> 
> 
> 

------------------------------------------------------------
IHMC                                     (850)434 8903 or (650)494 3973   
40 South Alcaniz St.           (850)202 4416   office
Pensacola                            (850)202 4440   fax
FL 32502                              (850)291 0667   mobile
phayesAT-SIGNihmc.us       http://www.ihmc.us/users/phayes
Received on Thursday, 8 November 2012 01:11:58 GMT

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