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Re: possible semantic bugs concerning domain and range

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Wed, 25 Sep 2002 18:47:32 -0400 (EDT)
Message-Id: <20020925.184732.125124176.pfps@research.bell-labs.com>
To: jonathan@openhealth.org
Cc: phayes@ai.uwf.edu, www-webont-wg@w3.org

From: "Jonathan Borden" <jonathan@openhealth.org>
Subject: Re: possible semantic bugs concerning domain and range
Date: Wed, 25 Sep 2002 17:24:47 -0400

> Peter F. Patel-Schneider wrote:
> 
> >
> > Suppose that you have the following:
> >
> >    foo rdfs:subPropertyOf bar .
> >    foo rdfs:range xsd:[integer union string] .
> >    bar rdfs:range xsd:[string union integer] .
> >
> >    john foo 10 .
> >
> > how is 10 to be interpreted?
> >
> 
> I'm a bit confused, perhaps you can write that out in legal N-triples?

It is not possible  to write [integer union string] in N-triples.

I should have been more explicit, and said that this was an XML-Schema
derived class.

> I assume you mean:
> 
> foo rdfs:range _:x .
> _:x unionOf (xsd:integer, xsd:string) .

Well, sort of, but the union would be in XML-Schema, not in OWL.

> and
> 
> john foo "10" .
> 
> as opposed to either
> 
> john foo xsd:integer"10" .
> or
> john foo xsd:string"10" .
> 
> this according to the latest changes to the still unfinished RDFCore
> datatyping work.
> 
> ok so it the issue of how to interpret the literal "10"? doesn't this depend
> on whether RDFCore decides that the _default_ type of an untyped literal is
> xsd:string? Or if not then the interpretation of "10" includes
> {xsd:integer"10", xsd:string"10"}?

Well, it depends on a lot of things, but one approach being touted for a
while in the RDF Core was to have "the" range of the property determine
which XML-Schema literal-to-value map to use.  However, this breaks down
when super-properties can have different ranges (with non-compatible
literal-to-value maps).

> Jonathan

peter
Received on Wednesday, 25 September 2002 18:47:42 GMT

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