W3C home > Mailing lists > Public > public-webont-comments@w3.org > May 2003

Re: OWL abstract syntax: -lite, -dl restrictions

From: Graham Klyne <gk@ninebynine.org>
Date: Wed, 14 May 2003 22:11:20 +0100
Message-Id: <5.1.0.14.2.20030514221055.03101058@127.0.0.1>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: public-webont-comments@w3.org

This response is fine, thank you.

#g
--

At 10:36 14/05/03 -0400, Peter F. Patel-Schneider wrote:
>In my previous message I forgot to either close the thread or ask if you
>needed any more information.
>
>I'm going to do both here.  :-)
>
>Please reply if there is anything more that needs to be done on this
>thread.
>
>Peter F. Patel-Schneider
>Bell Labs Research
>Lucent Technologies
>
>
>From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
>Subject: Re: OWL abstract syntax: -lite, -dl restrictions
>Date: Fri, 09 May 2003 15:00:27 -0400 (EDT)
>
> > From: Graham Klyne <gk@ninebynine.org>
> > Subject: OWL abstract syntax: -lite, -dl restrictions
> > Date: Tue, 06 May 2003 17:29:37 +0100
> >
> > > With reference to:
> > >    http://www.w3.org/TR/owl-semantics/syntax.html#2.3.1.2
> > > and
> > >    http://www.w3.org/TR/owl-semantics/syntax.html#2.3.2.3
> > >
> > > I see that for OWL-lite:
> > > [[
> > > restriction ::= 'restriction(' datavaluedPropertyID
> > > dataRestrictionComponent ')'
> > >              | 'restriction(' individualvaluedPropertyID
> > > objectRestrictionComponent ')'
> > > ]]
> > >
> > > But for OWL-DL:
> > > [[
> > > restriction ::= 'restriction(' datavaluedPropertyID
> > > dataRestrictionComponent { dataRestrictionComponent } ')'
> > >              | 'restriction(' individualvaluedPropertyID
> > > objectRestrictionComponent { objectRestrictionComponent } ')'
> > > ]]
> > >
> > > Is it intended that a restriction may have only one component in 
> OWL-lite?
> >
> > Yes, this is intended.
> >
> > > This restriction (sic) seems rather pointless, as I think an axiom 
> naming a
> > > class can be repeated with multiple single-component restrictions to
> > > achieve the same effect.
> >
> > The more-complex construction in OWL DL is strictly convenience, as there
> > it can always be replaced by an intersection.  However, in OWL Lite, this
> > replacement is not always (easily) possible, leading to difficulties as to
> > just what can be said in OWL Lite.
> >
> > > Also, I note that OWL-lite restrictions do not include the single-value
> > > form of restriction "Value( _ )".  Is this intended?
> >
> > Yes, this is as intended.  The Value(_) construction augments the
> > expressive power of the language and was not put in OWL Lite for this
> > reason.
> >
> > > (I see no purpose in raising a formal issue for this.)
> > >
> > > #g
> >
> > Peter F. Patel-Schneider
> > Bell Labs Research
> > Lucent Technologies

-------------------
Graham Klyne
<GK@NineByNine.org>
PGP: 0FAA 69FF C083 000B A2E9  A131 01B9 1C7A DBCA CB5E
Received on Thursday, 15 May 2003 04:01:36 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:43:28 GMT