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Re: Problem with damlsParameter

From: Daniel Elenius <danel698@student.liu.se>
Date: 21 Apr 2003 19:24:48 +0200
To: Bijan Parsia <bparsia@isr.umd.edu>, www-ws@w3.org
Message-Id: <1050945888.2154.1.camel@q85.ryd.student.liu.se>

> You reuse the label on a node and a property. The Graph is not the Thing.
> 

Ok.

> > In the graph representation, the way I understood it, properties are 
> > the (labelled) directed edges between the nodes (which can be classes 
> > or primitive values). How can an edge point to another edge?
> 
> Well, if we're doing visual reasoning it, I find it hard to see how 
> *not*. But such graph reasoning is, imho, to be avoided. If you check 
> out the RDF Semantics doc, and the one on RDFS, you'll see that a 
> property can be a class or an individual at the very same time.
> 
> > It doesn't make sense to me, and I can see why it doesn't make sense to 
> > the JTP reasoner, it being very logical after all :)
> 
> No, it just means that you don't have the right axioms.
> 

So what would be the right axioms in the case of damlsParameter for
instance?

> The case for DAML+OIL is tricky because, on some hands, it's a 
> description logic, and they frown upon having Properties as individuals 
> (though in the graph syntax for DAML+OIL, you'll see properties in 
> subject and object  positions: consider subProperty relations). On other 
> hands, it's supposed to build upon RDFS where that's not only kosher, 
> it's heartily encouraged.
> 
> OWL does somewhat better in defining two major variants, OWL/DL and 
> OWL/Full. The latter has the promiscuity of RDFS.
> 
> And none of this even touches on the fact that you can put an "opaque" 
> URI anywhere you like. I.e., if you have http://someProperty in one file 
> but don't *declare* it ot be a property, you "can" do whatever you like 
> with it. This is part of the motivation for the RDFS approach.
> 

Thanks for the info.

> [snipped the rest as I'm having trouble attending to it right now but 
> think the rest is important]
> 
> Cheers,
> Bijan Parsia.
> 
Received on Monday, 21 April 2003 13:24:38 GMT

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