Re: Reasoning

On 18/07/2011 11:24, Markus Krötzsch wrote:
> On 18/07/11 08:27, Cristiano Longo wrote:
>> Morning all,
>> in the far future I planned to implement a description logic reasoner.
>> May you give me some hints or pointers about the pratical (I yet know
>> the algorithm) for implementing such a reasoner?
> Dear Christian,
> description logics come in various flavours to match different 
> application areas. These different logics also match different 
> profiles of OWL: OWL EL, OWL QL, OWL RL, and OWL DL (there is also OWL 
> Full but its semantics is not description logics based though both are 
> compatible to some extent).
> EL, QL, RL are more lightweight for better scalability (for example 
> OWL RL has been implemented in distributed settings with billions of 
> assertions; and EL has been used to classify ontologies with hundreds 
> of thousands of classes in a few seconds; QL is meant for 
> ontology-based data access to large databases). OWL DL provides the 
> full modelling support of all DL features that OWL has. Lightweight 
> languages are genermayally easier to implement but any efficient 
> implementation will need a lot of engineering. Just implementing an 
> algorithm from a research paper will not lead to good results.
> So before you can start, you really need to decide which description 
> logic/OWL profile you want to support. This is closely related to 
> another important questions: why do you want to implement your own 
> tool instead of just using an existing one?
> Regards
> Markus
Since I discovered a description logic in which the consistency problem  
in NP-complete (cf. [1]), and I wander if this teoretical property is 
relevant in the real world, considering that non-deterministic 
computations cannot take place with the hardware that is actually available.

thank you,

[1] Domenico Cantone, Cristiano Longo, and Antonio Pisasale. Comparing 
Description Logics
with Multi-level Syllogistics: the Description Logic DL <MLSS^{×}_{2,m}> 
. In 6th Workshop on
Semantic Web Applications and Perspectives (SWAP), 2010.

Received on Monday, 18 July 2011 09:49:25 UTC