RE: question on "forest-like anonymous individuals" restriction of OWL 2 DL

Hello,

No, not really: since OWL 2 has inverse roles, the actual directionality of the
property assertions doesn't matter. That is, the role assertion

ObjectPropertyAssertion( a:hasDaughter _:b1 _:b2 )

is equivalent to

ObjectPropertyAssertion( InverseObjectProperty(a:hasDaughter) _:b2 _:b1 )

Now if the latter is circular, the former should be circular as well, given that
the two assertions are semantically equivalent.

Regards,

	Boris

> -----Original Message-----
> From: Michael Schneider [mailto:schneid@fzi.de]
> Sent: 27 June 2009 01:52
> To: Boris Motik
> Cc: OWL 1.1
> Subject: RE: question on "forest-like anonymous individuals" restriction of
> OWL 2 DL
> 
> Hi Boris!
> 
> The second counter example states
> 
>   ObjectPropertyAssertion( a:hasChild _:b1 _:b2 )
>   ObjectPropertyAssertion( a:hasDaughter _:b1 _:b2 )
> 
> But shouldn't it be
> 
>   ObjectPropertyAssertion( a:hasChild _:b1 _:b2 )
>   ObjectPropertyAssertion( a:hasDaughter _:b2 _:b1 )
>                                          ^^^^^^^^^
> 
> in order to build a circular structure?
> 
> Cheers,
> Michael
> 
> >-----Original Message-----
> >From: Boris Motik [mailto:boris.motik@comlab.ox.ac.uk]
> >Sent: Friday, June 26, 2009 1:29 PM
> >To: Michael Schneider; 'OWL 1.1'
> >Subject: RE: question on "forest-like anonymous individuals" restriction
> >of OWL 2 DL
> >
> >Hello,
> >
> >In response to Michael's comment, Ian and I have made the following
> >changes to
> >the Syntax document:
> >
> >http://www.w3.org/2007/OWL/wiki/index.php?title=Syntax&diff=24654&oldid=
> >24647
> >
> >I hope things are clearer now. Please let me know should you have any
> >comments.
> >
> >Regards,
> >
> >	Boris
> >
> >> -----Original Message-----
> >> From: public-owl-wg-request@w3.org [mailto:public-owl-wg-
> >request@w3.org] On
> >> Behalf Of Michael Schneider
> >> Sent: 29 May 2009 20:46
> >> To: OWL 1.1
> >> Subject: question on "forest-like anonymous individuals" restriction
> >of OWL 2
> >> DL
> >>
> >> Hi all!
> >>
> >> I had to explain to someone the "forest-like anonymous individuals"
> >> restriction of OWL 2 DL (Section 11.2 of the Structural Spec), but I
> >found
> >> myself uncertain about it. In particular, I'm unclear how "fixed" the
> >variable
> >> "OPE" is in the set of conditions.
> >>
> >> But it's easier to show my problem by an example: It's clear to me
> >(also from
> >> the example following the formal definition) that the following is
> >/not/
> >> allowed in OWL 2 DL:
> >>
> >>   _:x :p _:y
> >>   _:y :p _:x
> >>
> >> But what about
> >>
> >>   _:x :p _:y
> >>   _:y :q _:x
> >>
> >> with /different/ properties?
> >>
> >> Michael
> >>
> >> --
> >> Dipl.-Inform. Michael Schneider
> >> Research Scientist, Dept. Information Process Engineering (IPE)
> >> Tel  : +49-721-9654-726
> >> Fax  : +49-721-9654-727
> >> Email: michael.schneider@fzi.de
> >> WWW  : http://www.fzi.de/michael.schneider
> >>
> >=======================================================================
> >> FZI Forschungszentrum Informatik an der Universität Karlsruhe
> >> Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
> >> Tel.: +49-721-9654-0, Fax: +49-721-9654-959
> >> Stiftung des bürgerlichen Rechts, Az 14-0563.1, RP Karlsruhe
> >> Vorstand: Prof. Dr.-Ing. Rüdiger Dillmann, Dipl. Wi.-Ing. Michael
> >Flor,
> >> Prof. Dr. Dr. h.c. Wolffried Stucky, Prof. Dr. Rudi Studer
> >> Vorsitzender des Kuratoriums: Ministerialdirigent Günther Leßnerkraus
> >>
> >=======================================================================
> >>
> >
> 
> --
> Dipl.-Inform. Michael Schneider
> Research Scientist, Dept. Information Process Engineering (IPE)
> Tel  : +49-721-9654-726
> Fax  : +49-721-9654-727
> Email: michael.schneider@fzi.de
> WWW  : http://www.fzi.de/michael.schneider
> =======================================================================
> FZI Forschungszentrum Informatik an der Universität Karlsruhe
> Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
> Tel.: +49-721-9654-0, Fax: +49-721-9654-959
> Stiftung des bürgerlichen Rechts, Az 14-0563.1, RP Karlsruhe
> Vorstand: Prof. Dr.-Ing. Rüdiger Dillmann, Dipl. Wi.-Ing. Michael Flor,
> Prof. Dr. Dr. h.c. Wolffried Stucky, Prof. Dr. Rudi Studer
> Vorsitzender des Kuratoriums: Ministerialdirigent Günther Leßnerkraus
> =======================================================================

Received on Saturday, 27 June 2009 00:02:51 UTC