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List-valued Properties?

From: Kevin D. Keck <kdkeck@lbl.gov>
Date: Wed, 12 Nov 2003 13:46:42 -0800
To: public-webont-comments@w3.org
Message-Id: <200311121346.42946.kdkeck@lbl.gov>

It appears to me that OWL Lite and OWL DL provide no way to define a Property 
with bounded (and/or ordered), type-restricted values, other than by 
subclassing rdf:List or some similarly distateful kludge. For the same 
reasons which compelled the RDF Core group to add rdf:List to RDF (and some 
of which have led to a number of uses of Lists in OWL itself), I submit that 
it's important for OWL to be able to fully support Lists as RDF primitives 
distinct from owl:Classes.

For my current purposes, it would be entirely adequate to provide an 
"owl:List" form to be used as a third kind of range restriction, in addition 
to class descriptions and data ranges. It could have a single property (say 
"owl:memberType") specifying a class description, data range, or nested list 
description. E.g.:

<owl:ObjectProperty rdf:about="#cast">
  <owl:domain rdf:resource="#Show"/>
  <owl:range>
    <owl:List>
      <owl:memberType rdf:resource="#Actor"/>
    </owl:List>
  </owl:range>
</owl:ObjectProperty>

<ex:Show>
  <ex:cast parseType="Collection">
    <ex:Actor ex:name="Ahnuld"/>
    <ex:Actor ex:name="Madonna"/>
  </ex:cast>
</ex:Show>

Does this make sense (the proposal, not the example cast)?
-- 
Kevin D. Keck
http://vimss.lbl.gov/~kdkeck/
510-486-4856
Received on Wednesday, 12 November 2003 16:46:46 GMT

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