Re: Cardinality in the open world

On 14 Apr 2005, at 16:40, Bijan Parsia wrote:
> On Apr 14, 2005, at 10:28 AM, Enrico Franconi wrote:
>> Instance checking in OWL-Lite is NP-complete (recent result by Boris 
>> Motik) in data compexity,
>
> Interesting! Does he have a paper or tech report out on it?

It can be understood as a corollary of his KR'04 paper - even if he did 
not realise it at first. As such, I believe that the explicit result is 
still unpublished.
In short. NP-hardness in data complexity of instance checking for ALC 
was already known (folklore since Andrea Schaerf's PhD thesis in the 
early 90ies). Boris proves a reduction of instance checking of SHIQ in 
deterministic disjunctive datalog, which is NP-complete in data 
complexity; this proves the upper bound. Hence, instance checking is 
NP-complete in data complexity for ALC, SHIQ, OWL-Lite.
cheers
--e.

Received on Friday, 15 April 2005 08:01:30 UTC