Re: All humans love (all) cats

Hi Bijan,

Thanks for your  most erudite exposition of some aspects of OWL.

You wrote

.*..where's your proof that your representation above is equi-satisfiable
with the various OWL versions? If it is not, then you haven't solved it. The
burden of proof is, obviously, on you.*

It's likely that at least some of the versions of OWL are incomparable  with
Executable English / Internet Business Logic.  (i.e. There are overlapping
but distinct Vennn diagrams for expressivity)

However my question still appears to be on the table: what do we buy with
the added conceptual complexity** of OWL over EE/IBL rules?

As an expert on OWL who is also well read on the earlier work on
stratification, you can surely point us to further crisp examples that will
work in OWL but may pose a challenge for EE/IBL rules.

Thanks in advance,   -- Adrian


**See for example from the current discussion:

*"I feel rather miffed by the fact that such a simple and mundane-looking
FOL statement requires such an excruciatingly  complicated workaround in
order to be represented in OWL2.*"

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Adrian Walker
Reengineering


On Tue, Oct 5, 2010 at 6:03 PM, Bijan Parsia <bparsia@cs.man.ac.uk> wrote:

> On 5 Oct 2010, at 22:29, Adrian Walker wrote:
>
> > Hi Pavel --
> >
> > A belated reply to your note.
> >
> > The question I'm worrying at is that I'd like to understand what we buy
> with the added complexity of OWL over rules.
>
> Actually, I don't think it is.
>
> > You wrote: I'm not sure which semantics
> > your system implements.  The system is based on the model theoretic
> semantics in [1], with decidable and terminating computation as in [2].
>
> See, you *could* answer concretely here, but you don't. You could respond
> to the characterisation that Pavel and I conjectured, but you don't.
>
> Looking at: http://oai.cwi.nl/oai/asset/10404/10404A.pdf
>
> I see you interpret in minimal models. It's just Datalog.
> So, DL Safe rules is the closest. And Pavel is quite correct.
>
> > ...it would not entail, for example, that some subset of Person love cats
> (e.g. "men love cats" although men are persons).
> >
> > This also seems easy using rules, as follows [3]
> >
> > some-class1 is a subclass of some-class2
> > all people in that-class2 love items in some-class
> > ---------------------------------------------------
> > all people in that-class1 love items in that-class
>
> He didn't say that you couldn't create some sort of program that did
> something which one can loosely interpret as that inference.
>
> And, of course, it would help if you used a standard notation. (First order
> would be fine.)
>
> Markus posted links to his papers and his dissertation which discuss the
> representation problem in detail. Why not, you know, at least skim them to
> determine *the representation task*? Then you can try to, you know, perform
> it.
>
> To put it another way, where's your proof that your representation above is
> equi-satisfiable with the various OWL versions? If it is not, then you
> haven't solved it. The burden of proof is, obviously, on you.
>
> Cheers,
> Bijan.