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Re: Property chain axioms and cyclic dependencies

From: Michel Dumontier <michel.dumontier@gmail.com>
Date: Mon, 3 Jun 2013 01:14:13 +0200
Message-ID: <CALcEXf7YDboDtdtrpf0aBhWCZ2EUTObsBdsAk_agzBYkB-N=bA@mail.gmail.com>
To: Michael F Uschold <uschold@gmail.com>
Cc: Matías Parodi <mparodilabs@gmail.com>, "semantic-web@w3.org" <semantic-web@w3.org>
The relevant section is here:

http://www.w3.org/TR/owl2-syntax/#Global_Restrictions_on_Axioms_in_OWL_2_DL

basically, you can't use transitive roles and composed roles (e.g. from
property chain) in min/max/exactly/self axioms or in combination with
functional, inverse functional, irreflexive, asymmetric and disjoint
properties.  there's also restrictions on the property hierarchy, in that
the composed roles can't lead to a cycle (must maintain partial order; see
text for details), along with properties that have non-simple subproperties.

m.




On Sun, Jun 2, 2013 at 9:31 PM, Michael F Uschold <uschold@gmail.com> wrote:

> This is tricky, read very carefully the OWL spec.  There are obscure and
> bizare (from a common sense user perspective) restrictions that result from
> the inference needs.  Good luck.
>
>
> On Wednesday, May 29, 2013, Matías Parodi wrote:
>
>> Hello,
>>
>> I'm trying to understand in which cases it's allowed to use
>> owl:propertyChainAxiom and when it's not.
>>
>> I've written a small ontology to understand it (I pasted it at the end),
>> but I still couldn't figure out why HermiT (using Protege) says "The given
>> property hierarchy is not regular" and "There is a cyclic dependency
>> involving property :isRelative".
>>
>> I know there's a loop there but what is the real problem? After all, how
>> is that different from a owl:TransitiveProperty? Any way to intuitively
>> understand what is wrong with it?
>>
>> Any idea?
>>
>> Thank you,
>> Matt
>>
>> ---
>> @prefix : <http://foo/bar#>.
>> @prefix owl: <http://www.w3.org/2002/07/owl#>.
>> @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>.
>> @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>.
>> @prefix xsd: <http://www.w3.org/2001/XMLSchema#>.
>>
>> :Person a owl:Class.
>>
>> :isRelativeOf
>>   a owl:TransitiveProperty;
>>   rdfs:domain :Person;
>>   rdfs:range :Person;
>> ..
>>
>>   :isAncestorOf
>>     rdfs:subPropertyOf :isRelativeOf;
>>     owl:propertyChainAxiom (:isRelativeOf :isAncestorOf);
>>   .
>> ---
>>
>
>
> --
> Sent from an input-challenged device.
>



-- 
Michel Dumontier
Associate Professor of Bioinformatics, Carleton University
Chair, W3C Semantic Web for Health Care and the Life Sciences Interest Group
http://dumontierlab.com
Received on Sunday, 2 June 2013 23:15:05 UTC

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