- From: Bijan Parsia <bparsia@cs.man.ac.uk>
- Date: Sun, 3 Aug 2008 21:25:55 +0100
- To: "Michael Schneider" <schneid@fzi.de>
- Cc: <public-owl-dev@w3.org>, "Jeff Thompson" <jeff@thefirst.org>
On Aug 3, 2008, at 8:55 PM, Michael Schneider wrote: > Two questions for my interest: > > Bijan Parsia wrote: > >> On Aug 3, 2008, at 7:58 PM, Jeff Thompson wrote: > >>> And yet, the argument against >>> adding more expressiveness to OWL 2 (still decidable) is the fear >>> that not enough people will implement it and so that "OWL 2 >>> compliant" >>> won't mean much. >> >> What? The argument against boolean role boxes, in general, is that >> it's relatively hard to do and there's been relatively little demand >> for it. > > Question 1: Is sROIQ + role intersection known to be decidable? The > Complexity simulator [1] only tells me that concept satisfiability is > NExpTime hard, but there's no explicit statement that this language is > decidable. (For sROIQ, however, there exists such an explicit > statement.) > But maybe this statement has just been forgotten, or the entry is > not up to > date with the literature. So what's the state here? The navigator is, indeed, lagging. My best guess is that it is unknown. Uli? >> ALBO is *very* expressive but, you know, doesn't have >> cardinality restrictions. > > Question 2: I guess that the "B" stands for "[B]oolean role box", and > probably subsumes a few more language features, too, right? (I > don't find > "B" mentioned in the complexity simulator.) Indeed. ALBO subsumes the 2 variable fragment (L2). So, I guess the only question is how chains (i.e., transitivity) and number restrictions interact with the rest. C2 is decidable (obviously), so maybe it's all down to chains. Uli (again)? Cheers, Bijan.
Received on Sunday, 3 August 2008 20:26:37 UTC