- From: Enrico Franconi <franconi@inf.unibz.it>
- Date: Wed, 20 Dec 2006 17:25:54 +1300
- To: Bijan Parsia <bparsia@cs.man.ac.uk>
- Cc: "Gerd Wagner" <wagnerg@tu-cottbus.de>, "'Dave Reynolds'" <der@hplb.hpl.hp.com>, <public-owl-dev@w3.org>
(just to add some irrelevant noise to your mailboxes...) On 15 Dec 2006, at 09:49, Bijan Parsia wrote: > On Dec 14, 2006, at 8:32 PM, Gerd Wagner wrote: > >>> Remember that consistency and entailment are closely related, >>> e.g., P is entailed by O if O & ~P is inconsistent. >> >> Only for classical logic, but not for many non-classical >> logics that may be more relevant to KR than classical logic. > > Well this is so for RDF through OWL, which is, after all, what we > are *very specifically* talking about. With care... First of all, in RDF there is no negation, so the above can not even be stated. Also in OWL-DL there is no negation in statements. In DLs (like in modal logics - which are non-classical logics) the deduction theorem is not straightforwardly true. As a matter of fact, the reduction from entailment to satisfiability is done by using the internalisation process (e.g., by having or mimicking the universal role). ciao --e.
Received on Wednesday, 20 December 2006 04:27:45 UTC