- From: Alan Ruttenberg <alanruttenberg@gmail.com>
- Date: Wed, 7 Nov 2007 12:25:52 -0500
- To: Bijan Parsia <bparsia@cs.man.ac.uk>
- Cc: public-owl-wg@w3.org
On Oct 31, 2007, at 9:01 AM, Bijan Parsia wrote: > 3) Language extensions with "must understand". > > In C&P's implementation of probabilisitc extensions to OWL based on > the P-SHOQ formalism, > > <http://clarkparsia.com/weblog/category/semweb/probabilistic- > reasoning/> > > we used axiom annotations to turn subclass axioms into conditional > constraints (for example). A system cannot *correctly* ignore those > annotations, but it was a very convenient way to extend the > language (although one could argue that it was potentially > misleading): We didn't have to change any basic parsers or editors; > it worked in all syntaxes for free, etc. > > In general, better support for extensions is helpful. I'm a little worried about this, one, in the sense that the file advertises itself as OWL, but really isn't (it has different semantics). I'd worry that we would arrive at a situation in which there were all sorts of little "must understand" bits from different people, leading to one of two situations - either all should be rejected by reasoners, or the "what the heck, it's just a couple of axioms, let's ignore it". Would an alternative to define a different sort of file that has a way of embedding OWL, and then teach tools to use those files too? -Alan
Received on Wednesday, 7 November 2007 17:26:09 UTC