- From: Jeremy Carroll <jjc@hpl.hp.com>
- Date: Tue, 06 May 2008 10:47:19 +0100
- To: Boris Motik <boris.motik@comlab.ox.ac.uk>
- CC: "'OWL Working Group WG'" <public-owl-wg@w3.org>
> Unfortunately, this is a "feature" and not a bug. Complements of data ranges are included into OWL 2 mainly in order to provide > everything that is needed for reasoning: during reasoning, all concepts involving datatypes must be put into conjunctive normal > form, and this cannot be done unless we have data ranges. But then, the complement of data ranges *must* be defined w.r.t. the whole > domain, and not just the datatype being complemented; otherwise, using ComplementOf in order to put constructs into negation normal > form would be unsound. > > Therefore, this is somewhat unfortunate, but we have to live with it, I'm afraid. > I am assuming it is possible to express the intersection of the enclosing type with the complement - so that Michael's point is more about usability than expressability. I suspect that usability is a 'value added' feature of good OWL tools .... and not an inherent feature of the language :) Jeremy
Received on Tuesday, 6 May 2008 09:49:07 UTC