- 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
> 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 UTC