RE: Constraining Collections?

I wonder if you could get away with something like this:

rss:Channel rdfs:subClassOf 
 [ a owl:Restriction;
  owl:onProperty rss:items;
  owl:allValuesFrom 
   [rdfs:subClassOf rdf:Seq,
    [a owl:Restriction;
	owl:onProperty [a rdfs:ContainerMemershipProperty];
      owl:allValuesFrom rss:item
    ]
   ]
  ].	

The alternative would be pretty ugly:

rss:Channel rdfs:subClassOf 
 [ a owl:Restriction;
  owl:onProperty rss:items;
  owl:allValuesFrom owl:unionOf( 
   [rdfs:subClassOf rdf:Seq,
    [a owl:Restriction;
	owl:onProperty rdf:_1;
      owl:allValuesFrom rss:item
    ]
   [rdfs:subClassOf rdf:Seq,
    [a owl:Restriction;
	owl:onProperty rdf:_2;
      owl:allValuesFrom rss:item
    ]   
   ]
	...
  ].	

 
- Geoff

> -----Original Message-----
> From: semantic-web-request@w3.org [mailto:semantic-web-request@w3.org] On
> Behalf Of Brian Manley
> Sent: Tuesday, March 15, 2005 11:25 AM
> To: semantic-web@w3.org
> Subject: Constraining Collections?
> 
> 
> All,
> 
> Can rdf:Collection and friends be constrained? In RSS 1.0 for example,
> rss:items is supposed to reference a rdf:Seq containing only references to
> resources of type rss:item. However, this seems to be by convention rather
> than being formally specified in the schema. Is there are a way to do this
> in RDFS or OWL?
> 
> Many thanks!
> Brian
>