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Re: User-defined Datatypes: owl:DataRange vs rdfs:Datatype

From: Holger Knublauch <holger@topquadrant.com>
Date: Wed, 06 Dec 2006 16:48:30 -0800
Message-ID: <457764DE.2030005@topquadrant.com>
To: public-owl-dev@w3.org


Jeff Z. Pan wrote:
> Hi Holger,
>>
>> I am wondering why user-defined datatypes are not modeled as instances 
>> of the RDF Schema class rdfs:Datatype (similar to the hack suggested 
>> in the Protege 3 implementation [1]).  Without knowing the design 
>> decisions that lead to the use of owl:DataRange, my naive point of 
>> view would be that rdfs:Datatypes may make it more consistent with the 
>> semantic web stack.  I am sure the working group had good reasons for 
>> selecting owl:DataRange, but it would be useful to understand them 
>> from the outside.
>>
> In RDF, a datatype (instance of rdfs:Datatype) and a class (instance of 
> rdfs:Class) can share instances, such as the integer 42. While in OWL DL 
> (and hence OWL 1.1), the datatype domain is disjoint with the object 
> domain; therefore, sharing instances is not possible for an OWL DL/1.1 
> datatype and an OWL DL/1.1 class.
> 
> Greetings,
> Jeff

Thanks, Jeff.  But in RDF Schema, the pre-defined system datatypes such 
as xsd:int are instances of rdfs:Datatype as well [1].  Are user-defined 
datatypes different from system datatypes, or is OWL 1.1 changing the 
RDF Schema semantics here?  Apologies if this has been discussed and 
written down elsewhere - any pointers are appreciated.

Regards,
Holger

[1] http://www.w3.org/TR/rdf-schema/#ch_datatype
Received on Thursday, 7 December 2006 00:52:43 GMT

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