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Querying for individuals

From: Cristian Cocos <cristico@gmail.com>
Date: Tue, 01 Mar 2011 15:08:38 -0400
Message-ID: <4D6D4436.6050109@gmail.com>
To: pellet-users@lists.owldl.com, public-owl-dev@w3.org
-------- Original Message --------
Subject: Re: [Pellet-users] Querying for individuals
Date: Mon, 28 Feb 2011 18:56:46 -0500
From: Brandon Ibach <brandon@clarkparsia.com>
To: Alan Ruttenberg <alanruttenberg@gmail.com>,        "cristi@ieee.org" 
<cristi@ieee.org>,        Uli Sattler <sattler@cs.man.ac.uk>

Uh, yeah... what Alan said. :)

OWL's OWA and lack of the unique name assumption (UNA) can be rather
frustrating, when it comes to things like this, as you can find
yourself unable to get the reasoner to tell you something without
first explicitly saying it all (or almost all), yourself.  ("I want to
know if this statement is true!" "Well, is it?" "Yes!" "So, what are
you asking me for?")

When it comes to the uniqueness of individuals, I find a functional
data property to be quite handy, if the individuals have a convenient
unique identifier of some kind.  Otherwise, stepping outside of OWL
just a bit, Pellet does have a configuration option to enable a UNA
mode. [1]

Please consider returning this thread to the mailing list, at some
point, for the benefit of those that follow.

-Brandon :)

[1] http://clarkparsia.com/pellet/faq/una/

On Mon, Feb 28, 2011 at 12:56 PM, Alan Ruttenberg
<alanruttenberg@gmail.com> wrote:
> Are all the individuals asserted or inferred to be different from each other.  (exercise: what if they are not)
> -Alan
> On Feb 28, 2011, at 12:21 PM, Cristian Cocos <cristico@gmail.com> wrote:
>> On 2/22/2011 0:55, Brandon Ibach wrote:
>>> Not necessarily.  Given OWL's open world assumption, just because an
>>> individual isn't asserted to be a member of B doesn't mean it isn't.
>>> In other words, in order for Pellet to return an individual for the
>>> "not B" query, it has to be able to prove that the individual is not a
>>> member of B.
>> Thanks for all the answers. I made the following experiment: I *defined* the class B as being (equivalent to) owl:oneOf(list of all individuals in B), yet querying with "not B" still doesn't give me what I want. Isn't *that* supposed to give me the complementary of B?
>> Cheers,
>> C
>> --
>> Cristian Cocos
>> Post Doctoral Fellow
>> Centre for Logic and Information, StFX University 54B St. Mary's Street,
>> Antigonish NS, Canada B2G 2W5
>> Tel: + 1 (902) 867-4931, Fax: +1 (902) 867-1397
>> Current research: "Building Decision-Support Through Dynamic Workflow
>> Systems for Health Care"
Received on Tuesday, 1 March 2011 19:09:55 UTC

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