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Re: importing RDF and OWL

From: Dave Reynolds <der@hplb.hpl.hp.com>
Date: Sun, 11 May 2008 12:32:55 +0100
Message-ID: <4826D967.9010407@hplb.hpl.hp.com>
To: Jos de Bruijn <debruijn@inf.unibz.it>
Cc: Sandro Hawke <sandro@w3.org>, public-rif-wg@w3.org

Jos de Bruijn wrote:

  Sandro wrote:
>> * I don't really like the document IRI's being used as Context IRIs.
>>   It's useful, but I see it raising some problems when you start to
>>   formalize the notion of Contexts.     Let's make up some other IRIs
>>   and link them back to the documents.  :-/    Something like
>>      http://www.w3.org/2008/rif-context#OWL_DL
> 
> I would be fine with that.  Other opinions?

+1

>> * I'm a little concerned about your notion of promotion in a
>>   hierarchy of entailment regimes.  If we imagine a world with NAF, then
>>   promotion might be incorrect.  Maybe add a flag, so users have to
>>   explicitely "import with context = X" or "import with context >= X" ?
> 
> When importing RDF/OWL there can be only one context for all imports. 
> So, any ruleset with both "import with context= X" and "import with the 
> context=Y" be rejected.
> 
> Perhaps it would make sense to just specify one context for all imports.

Not sure I follow that but if it means what I think it means then I 
agree :-)

My preference would be to only allow one RDF/OWL context for a given 
rule set. If you import with two different contexts that's a error (or 
an undefined situation) rather than defining a promotion mechanism.

If you want to mix multiple entailment regimes then use the future 
modules mechanism.

Part of my motivation for this is that the context list should be openly 
extensible. For example, I suspect the OWL-R fragment currently being 
defined in the OWLWG may be very important for RIF. We might even want 
to predefine an IRI to refer to it (so long as we can do so without 
entangling the specs). That seems easier if there isn't a predefined 
promotion hierarchy to fit into.

>> * ... I think maybe "Context" can be thought of as "Language".  You're
>>   loading some data/rules/knowledge, and naming the language it's
>>   written in, in case it's not properly labeled (as RDF data is not).
> 
> Yes, that is probably be a better name.
> Other opinions?

I guess I'm OK with "Language" and prefer it over "Context" but it is 
more than just the language that is being referred to. How about 
"Entailment Regime"?

Dave
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Received on Sunday, 11 May 2008 11:33:35 GMT

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