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Re: TODO++: daml-ont TallThing

From: David Martin <martin@ai.sri.com>
Date: Fri, 03 Nov 2000 10:09:45 -0800
Message-ID: <3A02FF69.10B55D1@ai.sri.com>
To: Ian Horrocks <horrocks@cs.man.ac.uk>
CC: "McBride, Brian" <bwm@hplb.hpl.hp.com>, www-rdf-logic@w3.org
Brian --

Ian Horrocks wrote:
> 
> On November 1, McBride, Brian writes:
> > > > There are a couple of minor nits in the example ontology:
> > > >
> > > > 1) Father is desribed as having range Man, but presumably
> > > >    inherits domain Animal from Parent.  Mother is similar.
> >
> > A mother of a fox is not human.  I'd expect the domain and range
> > to match i.e. domain of mother is person if range is woman, or
> > range of mother is female animal if domain is animal.
> >
> > A real nit - sorry.
> >
> > Brian
> 
> This is another example of a point I made in an earlier discussion on
> rdf-interest, namely that domain and range restrictions are very
> strong assertions, and that a value restriction on the domain class is
> usually more appropriate.
> 
> For example, when the domain and range of a property P are restricted
> to classes D and R respectively, the intended meaning often is (or
> should be) that IF (i,j) is an instance of P AND i is an instance of D
> THEN j must be an instance of R. 

Being new to this list, this is the first I heard of such an
interpretation of domain and range restrictions, but it strikes me as
thoroughly counter intuitive.  Aren't the domain and range restrictions
expressed independently, and thus conceptually separate?  It seems to me
there is nothing about these restrictions that indicates they are tied
in the inferential way that you describe.  That's my main concern --
that a user of DAML-0 would be very unlikely to arrive at your suggested
interpretation based on intuition.

Could you please say more about why you think this should be the
intended meaning?

Regards,

-- David Martin

> This can be expressed in OIL (and
> DAML-O) using a value restriction on the class D.


> 
> e.g., in OIL:
> 
> <rdfs:class rdf:ID="D">
>   <oil:hasSlotConstraint>
>     <oil:has-value>
>       <oil:hasProperty rdf:resource="#P"/>
>       <oil:hasClass rdf:resource="#R"/>
>     <oil:has-value/>
>   <oil:hasSlotConstraint/>
> <rdfs:class/>
> 
> or in DAML-O
> 
> <Class ID="D">
>   <restrictedBy>
>     <Restriction>
>       <onProperty resource="#P"/>
>       <toClass resource="#R"/>
>     </Restriction>
>   </restrictedBy>
> </Class>
Received on Friday, 3 November 2000 13:08:26 UTC

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