Re: How to restrict conditional cardinalites?

Yoshio,

if my understanding is correct, then what you are asking for is what the
description logic people call the 'qualified cardinality restriction'.
And, indeed, you cannot express it in OWL.

This is one of the features that OWL1.1 guys are thinking of adding to
OWL in future:

http://www-db.research.bell-labs.com/user/pfps/owl/syntax-20060614.html

[Note that, for the time being, OWL1.1 is *not* a W3C work, though it
may become one, eventually...]

Ivan


Yoshio Fukushige wrote:
> 
> Hi OWLers,
> 
> I'm a kind of embarrassed to ask this, but
> 
> "Can one express restrictions on cardinality of a property value
> conditioned wrt to the Class of the value?"
> 
> e.g. Can one say in OWL
> "Any instance of Panasonic DVD-Recorder EX200V is accompanied with
> one and only one remote controller as an accessory"
> when any instance of EX200V is accompanied with one and only one power cable 
> as an accessory at the same time?
> 
> I think I can say:
> 
> ex:EX200V rdfs:subClassOf
>   [a owl:Restriction;
>    owl:onProperty ex:hasAccessory;
>    owl:hasValue [a ex:RemoteController]].
> 
> just to say 
> 
> "Any instance of EX200V is accompanied with one remote controller as an accessory."
> 
> However, to put a restriction on the number of the remote controller,
> if I say (in addition to the statement above)
> 
> ex:EX200V rdfs:subClassOf
>   [a owl:Restriction;
>    owl:onProperty ex:hasAccessory;
>    owl:cardinality "1"^^xsd:nonNegativeInteger].
> 
> It should mean that any EX200V doesn't come with any power cable as an accessory.
> 
> One awkward solution would be to introduce ex:hasRemoteController and put a cardinal restriction on
> that property.
> 
> Or can I say
> 
> ex:EX200V rdfs:subClassOf
>   [a owl:Restriction;
>    owl:onProperty ex:hasAccessory;
>    owl:hasValue [a ex:RemoteController]
>    owl:cardinality "1"^^xsd:nonNegativeInteger].
> 
> to express the conditioned restriction? 
> 
> Is there any other solution?
> 
> Thanks in advance.
> 
> Best,
> Yoshio
> fukushige.yoshio@jp.panasonic.com
> 

-- 

Ivan Herman, W3C Semantic Web Activity Lead
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