Re: ISSUE-3: REPORTED: Lack of anonymous individuals

Carsten Lutz <clu@tcs.inf.tu-dresden.de> said:

> 
> On Thu, 8 Nov 2007, gstoil@image.ece.ntua.gr wrote:
> >
> > Carsten Lutz <clu@tcs.inf.tu-dresden.de> said:
> >
> >>
> >> On Thu, 8 Nov 2007, gstoil@image.ece.ntua.gr wrote:
> >>>
> >>>> But *do* allow it in existential and universal restrictions.
> >>>
> >>> Sorry but I don't see where the definition differentiates between
> >>> SROIQ-QCR-concepts and SROIQ-valua/existential-concepts.
> >>>
> >>> For example, I don't see how the current algorithm could classify
> >>> {a:\not \exists uprop.Self} as inconsistent.
> >>
> >> I would have to look into the algorithm. Maybe Uli can comment on this.
> >> On the other hand, I don't care too much about this point. We are not
> >> formalizing this algorithm, we are designing OWL 1.1. And whether or not
> >> it is in that particular algorithm, I keep up my claim that it is
> >> technically not difficult. We should rather discuss whether we think
> >> it is useful enough to be included. I do.
> >
> > Well many things are usefull, but besides usefullness we also have to 
look
> > into "doability" in order not discover surprising things afterwards.
> > Although your feeling is that these are technically not difficult let me
> > have my doubts since if these could give you true anonymous individuals
> > which in turn are not easy, then maybe things are not so obvious.
> 
> Please look into the SROIQ paper, section "reduction of inference
> problems".  There it is explained that the universal role can be
> eliminated by a simple reduction.
> 

Hmmm. Interesting, but as it says this is a simulation of the universal 
role. And apparently a reflexive, symmetric and transitive super-role does 
not give you a total relation (as you said in your original mail). Does this 
have any impact on your technique on representing anonymous individuals?

Greetings,
-gstoil

> greetings,
>  		Carsten
> 
> --
> *      Carsten Lutz, Institut f"ur Theoretische Informatik, TU 
Dresden       *
> *     Office phone:++49 351 46339171   mailto:lutz@tcs.inf.tu-
dresden.de     *
> 



--

Received on Thursday, 8 November 2007 15:49:51 UTC