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Re: Use of XSD namespace in RDF recommendations

From: Richard Cyganiak <richard@cyganiak.de>
Date: Wed, 5 Sep 2012 14:58:21 +0100
Cc: public-rdf-comments@w3.org
Message-Id: <939CA18B-4C64-4910-9F0F-91CDF8956C3F@cyganiak.de>
To: Antoine Zimmermann <antoine.zimmermann@emse.fr>
Antoine,

On 5 Sep 2012, at 14:21, Antoine Zimmermann wrote:
> Tentative proposal. Do we need to point to OWL 2 Mapping to RDF Graphs?

No, I don't think so. Someone looking at the Abstract or Introduction of owl2-syntax should be able to find it.

> Note: the Web Ontology Language [OWL2] offers facilities for defining custom datatypes and can be serialised as an RDF graph. This makes possible to embed datatype definitions in an RDF document. However, processing custom datatypes defined this way requires an OWL 2 engine. For more details, see Section 9.4 of [OWL2]. http://www.w3.org/TR/owl2-syntax/#Datatype_Definitions

Thanks, not too bad! Here's a slight rewording, does this still sound ok?

[[
Note: The Web Ontology Language [OWL2] offers [facilities for formally defining custom datatypes](http://www.w3.org/TR/owl2-syntax/#Datatype_Definitions) that can be used with RDF. However, RDF implementations are not required to support these facilities.
]]

Best,
Richard


> 
> 
> AZ.
> 
> Le 04/09/2012 21:36, Richard Cyganiak a écrit :
>> Ivan, Antoine, Dan, Richard, Jeremy,
>> 
>> I guess I like the idea of informatively linking to both the 2006
>> SWBP Note on datatypes [1] and to the OWL 2 datatype definition
>> mechanism [2], stating that both XML Schema and OWL 2 provide
>> facilities for formally defining RDF datatypes, but that support for
>> neither mechanism is required for RDF.
>> 
>> Jeremy: Is [1] still considered up-to-date, or should we avoid
>> drawing attention to it?
>> 
>> Antoine, Ivan, Dan: Perhaps one of you wants to take a stab at
>> drafting a sentence that could be inserted into the Datatypes section
>> [3] as another Note?
>> 
>> Cheers, Richard
>> 
>> [1] http://www.w3.org/TR/swbp-xsch-datatypes/ [2]
>> http://www.w3.org/TR/owl2-syntax/#Datatype_Definitions [3]
>> http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-concepts/index.html#section-Datatypes
>> 
>> 
>> 
>> On 4 Sep 2012, at 18:38, Ivan Herman wrote:
>> 
>>> Dan,
>>> 
>>> the question is of course justified, but I should also add that, in
>>> fact, very very few people use xmls schema datatype definitions
>>> together with RDF, too. In both cases the difficulty is identical:
>>> to understand and process those datatypes an external 'tool' has to
>>> be brought in: either an xml schema or an owl processor... Mainly
>>> in a non-XML RDF world (ie, as Richard said, with a diminishing
>>> usage of RDF/XML) the chance of using XML schema based derived
>>> datatypes is getting smaller and smaller in my view.
>>> 
>>> I find the OWL 2 datatype definition possibilities one of the most
>>> interesting and potentially important part of OWL 2. I actually
>>> wish the relevant part of the specification was also made more
>>> known and possibly used in isolation; at present it is burried in
>>> the overall OWL 2 spec, which is of course not an easy read...
>>> 
>>> (Maybe it is worth some extra blog/note)
>>> 
>>> Ivan
>>> 
>>> --- Ivan Herman Tel:+31 641044153 http://www.ivan-herman.net
>>> 
>>> (Written on mobile, sorry for brevity and misspellings...)
>>> 
>>> 
>>> 
>>> On 4 Sep 2012, at 15:37, Dan Brickley<danbri@danbri.org>  wrote:
>>> 
>>>> On 4 September 2012 21:11, Antoine Zimmermann
>>>> <antoine.zimmermann@emse.fr>  wrote:
>>>>> FWIW, OWL 2 has a feature to define custom datatypes that can
>>>>> be written completely in RDF, without using XML Schema.
>>>>> 
>>>>> Your example for Chapman codes can be written as follows, in
>>>>> Turtle syntax:
>>>>> 
>>>>> @prefix geo:<http://www.example.com/geo#> @prefix
>>>>> xsd:<http://www.w3.org/2001/XMLSchema#> @prefix
>>>>> owl:<http://www.w3.org/2002/07/owl#> @prefix
>>>>> rdfs:<http://www.w3.org/2000/01/rdf-schema#>
>>>>> 
>>>>> geo:chapman-code  a  rdfs:Datatype; owl:equivalentClass  [ a
>>>>> rdfs:Datatype; owl:onDatatype  xsd:string; owl:withRestriction
>>>>> ( [xsd:pattern "[a-zA-Z]{3}"] ) ] .
>>>> 
>>>> Interesting! Are many of these showing up "in the wild" yet?
>>>> 
>>>> Dan
>>>> 
>>> 
>> 
>> 
>> 
> 
> -- 
> Antoine Zimmermann
> ISCOD / LSTI - Institut Henri Fayol
> École Nationale Supérieure des Mines de Saint-Étienne
> 158 cours Fauriel
> 42023 Saint-Étienne Cedex 2
> France
> Tél:+33(0)4 77 42 66 03
> Fax:+33(0)4 77 42 66 66
> http://zimmer.aprilfoolsreview.com/
> 
Received on Wednesday, 5 September 2012 13:58:54 UTC

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