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Re: Reflexive properties in OWL

From: Bikash Gyawali <bikashg@live.com>
Date: Mon, 27 Dec 2010 16:34:17 +0100
Message-ID: <BLU153-ds11825AEAA4F954662D5D03DE000@phx.gbl>
To: <nathan@webr3.org>
Cc: "Public Owl Mailing List" <public-owl-dev@w3.org>
Ok. Here is a small toy ontology that I am attaching here to represent my 
problem.

The scenario is that I have declared two classes("Paper" and "Author"), two 
properties("hasReferenceTo" and "haspublicationDate") and two 
individuals(one for each class). I want the 'hasReferenceTo' property to be 
transitive and reflexive, which I have done by defining the properties 
nature in the ObjectProperties Tab. Since both properties make sense only to 
the "Paper" class, I have mentioned them as a necessary condition inside the 
ClassDescription box for "Paper" class. The "Author" class, for the moment, 
has no necessary conditions declared.

After running the reasoner, I see that the individual of "Author" 
class("Author1") also gets the "hasReferenceTo" property assigned to 
itself(under the Propert Assertions box for the individual "Author1"). I 
think that it's because, as I mentioned before, the reflexive property is 
"smarter" as it always knows its domain and range beforehand and thus gets 
attached to any class. You can see that "hasAddress" property is not 
attached to this individual of Author class(because it was declared to be 
functional).

I hope I could make myself clear. I need some way to restrict the reflexive 
property propagating to all individuals. Please provide some ideas.


-----Original Message----- 
From: Nathan
Sent: Monday, December 27, 2010 3:58 PM
To: Bikash Gyawali
Cc: Public Owl Mailing List
Subject: Re: Fw: Reflexive properties in OWL

Just briefly, it appears to me that your trying to use closed world
assumptions rather than open world, where things can and do have
multiple "types" and what you can say about things isn't restricted.

It may be useful to post the ontology you're creating and give some more
info on what you're modelling.

Best,

Nathan

Bikash Gyawali wrote:
> 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?




Received on Monday, 27 December 2010 15:34:54 GMT

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