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Re: Exactly one element in a RDFS class

From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
Date: Mon, 17 Nov 2014 06:55:38 -0800
Message-ID: <546A0C6A.1070605@gmail.com>
To: Phil Archer <phil@philarcher.org>, Pavel Klinov <pavel.klinov@uni-ulm.de>, Victor Porton <porton@narod.ru>
CC: SW-forum Web <semantic-web@w3.org>
I'm having a very hard time coming up with any overlap between this discussion 
and anything that might happen in the RDF data shapes working group.  The 
working group is about detecting explicit information in RDF documents---this 
discussion is about how to create singleton classes, and maybe how to detect 
such singleton classes in an RDF encoding.

That said, SPARQL is used in several of the technologies being investigated by 
the working group and it is probably possible to write a SPARQL query to 
detect a singleton class in the RDF encoding of OWL, but this doesn't provide 
any true commonality.


On 11/17/2014 01:50 AM, Phil Archer wrote:
> This sort of debate is exactly the kind of thing that is behind the newly
> formed RDF Data Shapes working group. Its charter includes pointers to a bunch
> of existing work in this area that may be useful.
> See http://www.w3.org/2014/data-shapes/
> Cheers
> Phil.
> On 16/11/2014 23:03, Pavel Klinov wrote:
>> There's no simpler encoding. Nominals is the only feature in OWL 2
>> which lets you say that a class has a single instance. And it has a
>> unique serialization in RDF.
>> I don't think querying for this particular syntactic construct is complex.
>> However, writing RDF queries for OWL ontologies serialized in RDF (be
>> that SPARQL or other RDF graph matching language) is usually not a
>> great idea. You'll often have to deal with specifics of the RDF
>> serialization which is complex for many OWL constructs (see [1])
>> Cheers,
>> Pavel
>> [1] http://www.w3.org/TR/owl2-mapping-to-rdf/
>> On Sun, Nov 16, 2014 at 11:35 PM, Victor Porton <porton@narod.ru> wrote:
>>> Your solution has the same problem as Patrick Logan's one. (See my previous
>>> email.) In fact your solution is the same as Patrick Logan's one.
>>> 17.11.2014, 00:28, "Pavel Klinov" <pavel.klinov@uni-ulm.de>:
>>>> Sorry, my previous email got sent too soon.
>>>> Here's the link to the right place in the OWL 2 spec:
>>>> http://www.w3.org/TR/owl2-syntax/#Enumeration_of_Individuals
>>>> Cheers,
>>>> Pavel
>>>> On Sun, Nov 16, 2014 at 10:52 PM, Victor Porton <porton@narod.ru> wrote:
>>>>>   Is there any advise on how to code in RDFS or OWL the following statement?
>>>>>   "The class X has exactly one element."
>>>>>   --
>>>>>   Victor Porton - http://portonvictor.org
>>> --
>>> Victor Porton - http://portonvictor.org
Received on Monday, 17 November 2014 14:56:06 UTC

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