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Re: Reflexive properties in OWL

From: Bikash Gyawali <bikashg@live.com>
Date: Tue, 28 Dec 2010 13:39:20 +0100
Message-ID: <BLU153-ds21441CE7515A333AA35516DE010@phx.gbl>
To: "Marco Colombetti" <colombet@elet.polimi.it>, "Michael Schneider" <schneid@fzi.de>
Cc: "Public Owl Mailing List" <public-owl-dev@w3.org>
I see your point, Marco. So, there's no way to model properties that are 
both locally reflexive and transitive in OWL? In real life, there are 
properties like that, for eg: the hasReferenceTo property or 'Knows' 
property.

Bikash Gyawali

-----Original Message----- 
From: Marco Colombetti
Sent: Monday, December 27, 2010 7:21 PM
To: Bikash Gyawali ; Michael Schneider
Cc: Public Owl Mailing List
Subject: Re: Reflexive properties in OWL

Bikash, if I understood well another message of yours, you
want a property to be both transitive and locally
reflexive. This is not possible, because transitive
properties are composite, and you cannot apply a
self-restriction to a composite property.

Marco

On Mon, 27 Dec 2010 18:26:05 +0100
  "Bikash Gyawali" <bikashg@live.com> wrote:
> Hi Michael,
>
> So good to get an exact answer for what I looked for. I didn't know that 
> "new" feature before.
>
> Thanks.
>
> -----Original Message----- From: Michael Schneider
> Sent: Monday, December 27, 2010 6:12 PM
> To: Bikash Gyawali
> Cc: Public Owl Mailing List
> Subject: RE: Reflexive properties in OWL
>
> Hi Bikash,
>
> to define a property :p to be "locally-reflexive" w.r.t. class :C, make :C 
> a
> subclass of the self-restriction on :p (new feature of OWL 2):
>
>    :C rdfs:subClassOf [
>        rdf:type owl:Restriction ;
>        owl:onProperty :p ;
>        owl:hasSelf "true"^^xsd:boolean ] .
>
> This can be read as follows: For every instance x of class :C the 
> reflexive
> property assertion x :p x holds.
>
> If you want to additionally ensure that the only reflexive triples for :p
> are those with values from :C, then replace "rdfs:subClassOf" by
> "owl:equivalentClass" in the above axiom.
>
> Michael
>
>From: public-owl-dev-request@w3.org [mailto:public-owl-dev-request@w3.org]
> On Behalf Of Bikash Gyawali
> Sent: Monday, December 27, 2010 1:52 PM
> To: Public Owl Mailing List
> Subject: Fw: Reflexive properties in OWL
>
> Hello All,
>
> The specification of domain and range for any property doesn't act as
> constraint.
> It just acts as an axiom in OWL.
> So, I am just creating properties (without specifying their domain and
> roles). Later,I create restrictions on the property belonging to that
> respective class.
>
> However, I see a problem in reflexive properties.
> The reflexive property is automatically being assigned to all classes
> in the ontology. I don't want that to happen. When I create a reflexive
> property,
> I intend to act it so only for my particular class of choice.
>
> With other types of properties, this is not a problem.
> The reflexive property is "smarter" because it always knows its domain
> and role beforehand. So, its getting attached to all classes in the
> ontology.
>
>
> How can I restrict the reflexive property to a particular class?
>
> --
> Dipl.-Inform. Michael Schneider
> Research Scientist, Information Process Engineering (IPE)
> Tel  : +49-721-9654-726
>Fax  : +49-721-9654-727
> Email: michael.schneider@fzi.de
> WWW  : http://www.fzi.de/michael.schneider
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> Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
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>
>
>
Received on Tuesday, 28 December 2010 12:39:59 GMT

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