W3C home > Mailing lists > Public > public-rdf-wg@w3.org > November 2012

Re: Sloppy inference rules

From: Ivan Herman <ivan@w3.org>
Date: Wed, 7 Nov 2012 20:02:33 -0500
Message-Id: <0086CAEE-368C-4142-B3BC-1E793002CB76@w3.org>
Cc: Richard Cyganiak <richard@cyganiak.de>, Guus Schreiber <guus.schreiber@vu.nl>, RDF WG <public-rdf-wg@w3.org>
To: Pat Hayes <phayes@ihmc.us>
Ah! I think you misunderstood me. I did not mean to exchange bnodes in general; I realize that this would not work.

 What I meant was the following. The current rule set associates each literal with a fresh bnode; my understanding is that a new graph is created replacing each literal with this associated counterpart for the rule engine; at the end of processing these bnodes are switched back to the original literals. What I meant is that, today, we could those associations using skolems I believe instead of bnodes. 

Of course, if we use the generalized triple approach for the rules then that full association business becomes unnecessary...

Ivan

---
Ivan Herman
Tel:+31 641044153
http://www.ivan-herman.net

(Written on mobile, sorry for brevity and misspellings...)



On 7 Nov 2012, at 19:22, Pat Hayes <phayes@ihmc.us> wrote:

> 
> On Nov 7, 2012, at 9:34 AM, Ivan Herman wrote:
> 
>> 
>> On Nov 7, 2012, at 10:17 , Pat Hayes wrote:
>> 
>> 
> .............
>>> So, no, you can't just use skolem URIs instead of bnodes in inference rules. The resulting rules would not even be logically valid. 
>> 
>> Interesting. Just for my intellectual curiosity: can you clarify that?
> 
> Sure. Take a simple example.
> 
> _: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.
> 
> Pat
> 
> 
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Received on Thursday, 8 November 2012 01:03:00 GMT

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