[DL] question: complex role inclusion axioms

[Ian Horrocks]

On 22 Sep 2006, at 15:26, davide wrote:

> I have been looking in the literature for DLs enabling role 
> hierarchies including comlex inclusion axioms such as, for instance:
> R \bullet S \sqsubseteq Q (the composition of R and S is a sub-role of 
> Q).
>
> For DLs as expressive as Dynamic logic (or some relevant fragments) 
> this shouldn't be anything problematic since such axioms seem to be 
> translatable in  Dynamic logic. For instance:
> [Q]p \rightarrow [R][S]p
>
> Is this a correct intuition? Are there any references systematically 
> adressing the issue of complex role inclusions?
> Thanks a lot for your attention.

It is correct, although care is required when they are combined with 
cardinality restrictions (graded modalities). See 
http://www.cs.man.ac.uk/~ezolin/logic/complexity.html for details of 
this and much more.

Ian

>
> Davide
>
> -- 
> ===============================================
> Davide Grossi
> Intelligent Systems Group
> Institute of Information and Computing Sciences
> Universiteit Utrecht
> phone : +31 - 30 - 253 4432
> fax   : +31 - 30 - 251 3791
> http://www.cs.uu.nl/staff/davide.html 
> ===============================================
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