Re: (Round 2) Proposed Extensions to OWL

I think you're jumping to a wrong conclusion here.
Seems to me if cardinality of length is 1,
an OWL inference would conclude that the input contains a contradiction,
and one of the two lengths is wrong.

Dick McCullough
knowledge := man do identify od existent done;
knowledge haspart proposition list;

----- Original Message ----- 
From: "Benja Fallenstein" <b.fallenstein@gmx.de>
To: "Roger L. Costello" <costello@mitre.org>
Cc: <www-rdf-interest@w3.org>; <jon@spin.ie>; <tpassin@comcast.net>
Sent: Thursday, July 03, 2003 10:17 AM
Subject: Re: (Round 2) Proposed Extensions to OWL


> 
> Roger L. Costello wrote:
> > Document #1 shows the length in kilometers:
> > 
> > <River rdf:ID="Yangtze">
> >     <length>
> >         <Length>
> >             <measurement>
> >                 <LengthInKilometers>
> >                     <number>6300</number>
> >                 </LengthInKilometers>
> >             </measurement>
> >         </Length>
> >     </length>
> > </River>
> > 
> > Document #2 shows the length in miles:
> > 
> > <River rdf:ID="Yangtze">
> >     <length>
> >         <Length>
> >             <measurement>
> >                 <LengthInMiles>
> >                     <number>3914</number>
> >                 </LengthInMiles>
> >             </measurement>
> >         </Length>
> >     </length>
> > </River>
> ...
> > Question: what is the role of OWL with respect to these models?  Should
> > an OWL document be responsible for stating the conversion factor among
> > models?  
> 
> If we ignore (for the purposes of brainstorming) the problem of 
> precision, we can state using OWL that--
> 
> - the object of 'length' is a 'Length' with cardinality 1
> - the subject of 'measurement' is a 'Length' with cardinality 1
> 
> Let's say we know the above, your two documents, and a third document:
> 
> <Distance>
>      <from rdf:resource="#myHome"/>
>      <to   rdf:resource="#yourHome"/>
>      <length>
>          <Length>
>              <measurement>
>                  <LengthInMiles>
>                      <number>3914</number>
>                  </LengthInMiles>
>              </measurement>
>          </Length>
>      </length>
> </Distance>
> 
> Then we can conclude--
> 
> - The two Length resources of the Yangtze river are the same 
> (sameIndividualAs), because the object of the 'length' property has 
> cardinality 1.
> 
> Hmm... If we somehow could also state that two LengthInMiles with the 
> same 'number' are the same resource, then (and only then) we could go on 
> to conclude that--
> 
> - The two Length resources measured in miles are the same resource, 
> because they have the same measurements (subject has cardinality 1); and 
> therefore,
> 
> - all the three Length objects are the same resource; and therefore,
> 
> - the distance from my home to your home is 6300 kilometers.
> 
> However (as I realized while typing) this only works if we can state 
> that two <LengthInMiles number="xxx"/> are the same resource if xxx is 
> the same. Argl!
> 
> It *would* work-- even if that's less attractive-- if we did this:
> 
> <River rdf:ID="Yangtze">
>      <length>
>          <Length len:lengthInMiles="3914"/>
>      </length>
> </River>
> 
> Then we could state that both lengthInMiles and lengthInKilometers are 
> 1:1 properties, and thus conclude equivalence by example as above.
> 
> - Benja
> 
>

Received on Thursday, 3 July 2003 18:53:14 UTC