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Re: Explicit RDF property for "literal has datatype D"?

From: Jiří Procházka <ojirio@gmail.com>
Date: Mon, 04 Jan 2010 14:58:07 +0100
Message-ID: <4B41F3EF.3030709@gmail.com>
To: Dave Reynolds <dave.e.reynolds@googlemail.com>
CC: Semantic Web <semantic-web@w3.org>
Hmm I guess you are right
(http://www.w3.org/TR/rdf-concepts/#section-Literal-Equality).
I guess some property would have to be created:

_:x rdf:type xsd:date .
_:x todo:value "2008-01-01" .

todo:value rdfs:domain rdfs:Literal . # well, typed literal, no such
					class exists (yet)
todo:value rdfs:range rdfs:Literal . # well, plain literal :)

that should be equivalent to saying:

_:x owl:sameAs "2008-01-01"^^xsd:date .

Best,
Jiri

On 01/04/2010 09:28 AM, Dave Reynolds wrote:
> Jiří Procházka wrote:
>> Sorry for resurrecting this old thread, but I just stumbled upon this:
>>
>> "rdfs:Datatype is both an instance of and a subclass of rdfs:Class. Each
>> instance of rdfs:Datatype is a subclass of rdfs:Literal."
>>
>> "A typed literal is an instance of a datatype class."
>>
>> citing http://www.w3.org/TR/rdf-schema/#ch_datatype
>>
>> So I think this is valid:
>>
>> _:x rdf:type xsd:date .
>> _:x owl:sameAs "2008-01-01" .
> 
> Not as such, did you mean:
> 
>  _:x rdf:type xsd:date .
>  _:x owl:sameAs "2008-01-01"^^xsd:date .
> 
> ? Which would, I believe, be valid.
> 
> Dave
> 
>>
>> Quite confusing, but might be useful for RDF systems which treat
>> literals as just one "type" (type from their point of view).
>>
>> Shame there is no such thing for language tags, or is there?
>>
>> Best,
>> Jiri Prochazka
>>
>> On 07/06/2009 07:43 PM, Jeremy Carroll wrote:
>>> Pat Hayes wrote:
>>>>>> p a rdf:Property ;
>>>>>>  rdfs:domain rdfs:Literal ;
>>>>>>  rdfs:range rdfs:Datatype .
>>>>
>>>> _:x p xsd:date .
>>>> _:x :seenAsLiteral  "2008-01-01" .
>>> I tend to write these examples as
>>>
>>> _:x p xsd:date .
>>> _:x owl:sameAs  "2008-01-01" .
>>>
>>> Semantically that has a literal as the subject, and it works around the
>>> legacy syntactic restriction
>>>
>>> Unfortunately the reasoning required to make this work means that simple
>>> RDF systems may well not get it.
>>>
>>> Jeremy
>>>
>>>
>>>
>>
> 


Received on Monday, 4 January 2010 13:58:45 UTC

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