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Re: ACTION Bijan: to work on "closeOver" work-alike with

From: <jos.deroo@agfa.com>
Date: Mon, 7 Mar 2005 22:32:39 +0100
To: bparsia@isr.umd.edu
Cc: kendall@monkeyfist.com, DAWG Mailing List <public-rdf-dawg@w3.org>
Message-ID: <OFC65A1FA3.9070A7FB-ONC1256FBD.0072537D-C1256FBD.00765855@agfa.com>

Bijan wrote:
> On Mar 7, 2005, at 1:47 PM, Kendall Clark wrote:
>> On Mon, Mar 07, 2005 at 10:55:45AM -0500, Bijan Parsia wrote:
>>> If the action was to show the feasibility, then it is completed.
>> I think I understand what you've done. But my only concerns are
>>   1. Jos's case of being able to say that a graph is closed over an
>>      arbitrary (?) set of rules
> They just need an URI denoting them as an individual. That could be a 
> member of the class Expressivity.

OK, URI's are fine and what I did last 5 years was using such
expressivities which can be passed as command line argument
and have an internal mapping to load appropriate rule sets

else if (el.verb.startsWith(RDF)) return 
else if (el.verb.startsWith(RDFS)) return 
else if (el.verb.startsWith(XSD)) return 
else if (el.verb.startsWith(OWL)) return 

on top of that (for builtins, owl comprehension axioms, ...)
one can also source triples from


>>   2. the point that Bijan raises in a later message; that, for
>>      example, a graph may be closed over only the "interesting" subset
>>      of, say, RDFS entailments... Maybe there's not a real need to be
>>      able to say something this specific in the service description,
>>      but I can imagine a client taking "RDFS closure" in a strong way,
>>      querying for some triple that's inferred by one of the RDFS
>>      entailment rules that a particular graph *doesn't* implement...
> [snip]
> Well, I was thinking more of this.

me too :) and I remember that I had quite a hard time to do
just plain rdf inferencing (had to switch off all stuff like
builtin substitution of equals for equals, builtins, owl
comprehension, ...)

> Suppose I am 3Store and I always aggressively do RDFS closure. I can't 
> *not* query the RDFS closure.
> Suppose I am am Sesame, which can turn off RDFS closure, but have it on 
> too.
> These seem interestingly distinct.
> Now suppose there is a graph whose RDF and RDFS closure is identical 
> (are there any? hmm. I'll have to check).

never thought about that :)

> Then, these stores would 
> return the same hits. So it seems a little odd to say that 3Store 
> *doesn't* do RDF closure. It doesn't *filter out* RDFS (only) 
> entailments.
> I'm not sure it matters, but it did occur to me. In a class 
> representation of expressivity, you might want RDFExpr to be a subclass 
> of RDFSExpr and so on. But that wouldn't mean you could do *only* rdf 
> expr if you did RDFSExpr.


btw Bijan, in
I was not quite sure what was meant with
    :RDFSGraph  rdf:rest ();

> Cheers,
> Bijan.

Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
Received on Monday, 7 March 2005 21:33:23 UTC

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