Hello Pat, (01)
sorry for the late answer - I was quite busy. (02)
On Sun, Nov 18, 2012 at 04:06:51PM -0800, Pat Hayes wrote:
[MB]
> > I am confused by the Wikipedia article about OWL:
> >
> > https://en.wikipedia.org/wiki/Web_Ontology_Language#OWL_DL
> >
> > It says that "OWL DL was designed to provide the maximum expressiveness
> > possible while retaining computational completeness (either phi or not phi
> > belong), decidability (there is an effective procedure to determine whether
> > phi is derivable or not)".
> >
> > The statement about computational completeness of OWL DL is wrong, isn't it
>?
>
> I had a *huge* fight with the DL people (mostly Ian Horrocks) about this.
>Ian's view is that logics that aren't decideable are simply faulty, broken,
>inadequate, not of interest, etc.. Any "reasonable" logic should be
>decideable. So, he simply *assumes* decideability as a basic property of a
>logic. OK, that settled, we turn to completeness. If the logic is decideable,
>then one can phrase completeness as there being an effective procedure to
>determine entailment. (03)
Doesn't decidability already imply this by definition ?
http://en.wikipedia.org/wiki/Decidability_%28logic%29 suggests this to me. (04)
I do not have a clue what the term "computational completeness" in (05)
https://en.wikipedia.org/wiki/Web_Ontology_Language#OWL_DL (06)
means. The word "completeness" links to the article about complete theories
and the addition "(either phi or not phi belong)" also suggests this sense.
But surely, OWL DL does allow incomplete theories. (07)
Regards, (08)
Michael Brunnbauer (09)
--
++ Michael Brunnbauer
++ netEstate GmbH
++ Geisenhausener Straße 11a
++ 81379 München
++ Tel +49 89 32 19 77 80
++ Fax +49 89 32 19 77 89
++ E-Mail brunni@xxxxxxxxxxxx
++ http://www.netestate.de/
++
++ Sitz: München, HRB Nr.142452 (Handelsregister B München)
++ USt-IdNr. DE221033342
++ Geschäftsführer: Michael Brunnbauer, Franz Brunnbauer
++ Prokurist: Dipl. Kfm. (Univ.) Markus Hendel (010)
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/
To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J (011)
|