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Re: RDFS compatibility information in OWL-DL documents

From: Xiaoshu Wang <wangxiao@musc.edu>
Date: Thu, 19 Apr 2007 11:57:55 -0400
Message-ID: <46279183.80102@musc.edu>
To: Bijan Parsia <bparsia@cs.man.ac.uk>
CC: Alan Ruttenberg <alanruttenberg@gmail.com>, Jeremy Carroll <jjc@hpl.hp.com>, public-owl-dev@w3.org, Tim Berners-Lee <timbl@w3.org>, Alistair Miles <a.j.miles@rl.ac.uk>

Bijan,
> That also is specious, IMHO. First it conflates two things, 1) whether 
> there is an autoinclude or a explicit include mechanism and 2) whether 
> owl:imports can be legally used in this case.
>
> In point of fact, it can with no discernable difficulty. And even if 
> it couldn't, that doesn't preclude an explicit model. Indeed, it 
> strongly supports it (i.e., merging graphs is outside standard RDF).
I didn't say it can't.  I was just saying, if there is auto-include, 
what is the point of explicit include?  What kind of difference does it 
make? 
> So you are free to follow your nose in your tools, but if I am using 
> your tools I shall complain unless there is an opt out by default.
>
>> (If it is, then what isn't?)
>
> I'm fine with every rdf graph being an owl:Ontology. In point of fact, 
> they are (at least owl full). So that's fine.
I totally agree that every rdf graph is an ontology.  But then, 
shouldn't be owl:imports be relaxed to not constraining its domain to 
owl:Ontology.  And, then, what is the point of owl:Ontology? Shouldn't 
it be removed?
> Second, your example contains a subclass statement which is generally 
> an ontology statement. So this is a *good* example of an ontology (if 
> small).
Of course, I consider http://example.com/o1 an ontology.  That is not 
the question, the question is if the statement

_:x a http://example.com/o1#A

is an Ontology? (I cannot do the owl:imports here but not at 
http://example.com/o1)

>> And since there is no RDF/RDFS vocabularies that are given an 
>> "import/include" role, the only logical conclusion is that RDF must 
>> be using a "nose" model.
>
> Far from being the *only* logical conclusion, it's a non sequitur 
> (that is, not even logical).
>
>> This also makes sense since one of the essential features of the web 
>> is "self-descriptive" and a "nose" model fits in satisfactorily.
>
> Non sequitur number 2!
Sequitur or not. :-) I am still not sure what is your position on the 
answer to my example?

Fact: _:x a http://example.com/o1#A
Question: _:x a http://example.com/o2#B?

What should be the desired answer in semantic web?

Similarly, if I say to you that "I am a person"? What will be your 
answer to the question if I am a mammal?

Now, imaging two machine agents are communicating? What does it means if 
agent A said to agent B that
_:x a http://example.com/o1#A?  Not much beyond this sentence or 
potentially a lot more?

> Now you're being prescriptive. A conforment reasoner *must not*, in 
> it's conforming behavior, do what you claim it has to. That doesn't 
> preclude a larger *system* from doing this, to my mind, typically 
> useless, behavior.
But if there is no standard behavior prescribed, how do we communicate 
with clarity?  I thought the whole point of semantic web is to be 
explicit and unambiguous, right?
> If I use an URI in an RDF or OWL document I publish, I intend nothing 
> more to get into that document than the what's in the imports closure. 
> If you add extra stuff that's your look out.
I don't have problem with explicit import model. The problem that I have 
is the ambiguity in the current RDF and OWL spec.

First, standard "import" behavior needs to be explicitly described.
Second, depending on how the above question is answered, owl:imports, 
(perhaps, owl:Ontology and OntologyProperty as well) needs to be revised 
accordingly.

Cheers,

Xiaoshu

 
Received on Thursday, 19 April 2007 16:01:34 GMT

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