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Re: rdfs:Property rdfs:range questions

From: Jeen Broekstra <jeen.broekstra@aidministrator.nl>
Date: Fri, 20 Sep 2002 13:13:21 +0200
Message-ID: <3D8B02D1.2070104@aidministrator.nl>
To: m batsis <mbatsis@netsmart.gr>
CC: www-rdf-interest@w3.org

m batsis wrote:

 > * Can someone please point to what a property range defaults to?

It does not default to anything. If the range is unspecified, then
that's it: no range. Same for domain.

 > * IF I am correct, when a property has multiple ranges, all of them
 > must be satisfied (does not make sence to me;-). Can someone please
 > explain the reasons behind this?

There is an interesting discussion about this in the mailinglist
archives (actually, there are several :)), that may shed some light on
this. One possibly interesting thread starts at

The issue can also be found the in the RDF issue list that the RDF Core
WG maintains:


 > * How can I have two dissjoint ranges in the same property?

You can't.

Or actually you can, but then no instances can exist that use this property.

By the way, most[1] inferencers over RDF Schema interpret the
domain/range property semantics as inference rules rather than
constraints, which basically means that whenever you introduce a
property p with a certain range R (p rdfs:range R), and you introduce a
instance a with that property (a p b), its value is automatically
derived to be of type R (b rdf:type R).



[1] for sufficiently low values of most, that is :)
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Received on Friday, 20 September 2002 07:14:17 UTC

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