Re: A solution to integrate CWA into OWA.

On 3 Mar 2011, at 20:58, Juan Sequeda wrote:

> So, does OWL 2 have the epistemic operator?

No. OWL 2 has no nonmonotonic features. It's a fragment of first order logic. If you need this, SPARQL can help and so can various extensions.

> I'm just now digging into OWL2 but I can't find it anywhere. I would like to represent a foreign key constraint in OWL and it seems that it can't be done without the epistemic operator.

There's a kind of first order key in OWL2 which covers a lot of cases.

Incorporating non-monotonic operators into OWL is a challenging thing -- lots of proposals have been floated around and none have gotten large scale support. Aside from classic non-mon DLs, SPARQL, and various rule proposals, there's some integrity checking stuff in Pellet: http://clarkparsia.com/pellet/icv/

Cheers,
Bijan.