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Re: Help needed. Isn't this OWL document inconsistent?

From: Mekan Ikzain <mekanikzain@gmail.com>
Date: Mon, 26 Sep 2005 20:37:54 +0900
Message-ID: <ccae505f050926043713c42e75@mail.gmail.com>
To: www-rdf-logic@w3.org
Thanks for the comment!
Here're what I have learned so far.

1) Unsatisfiable concepts in an OWL document do not make the document
inconsistent.
2) If an instance of any unsatisfiable concept is introduced into the
document, the document becomes inconsistent.

Well, any error in the statements? Quite natural now it seems. ;-)

So, the following document contains one unsatisfiable concept, a:MadCow.

@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>.
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>.
@prefix owl: <http://www.w3.org/2002/07/owl#>.
@prefix a: <http://www.ex.org/2005/ex#>.

a:Vegetarian
owl:intersectionOf
(a:Animal
[a owl:Restriction;
owl:onProperty a:eats;
owl:allValuesFrom a:Plant
]
).
a:Plant owl:complementOf a:Animal.
a:Sheep rdfs:subClassOf a:Vegetarian.
a:Cow rdfs:subClassOf a:Vegetarian.
a:MadCow
owl:intersectionOf
(a:Cow
[a owl:Restriction;
owl:onProperty a:eats;
owl:someValuesFrom a:Sheep
]
).

And, the following document, which contains an instance a:MadDolly of
a:MadCow class, is inconsistent.

@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>.
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>.
@prefix owl: <http://www.w3.org/2002/07/owl#>.
@prefix a: <http://www.ex.org/2005/ex#>.

a:Vegetarian
owl:intersectionOf
(a:Animal
[a owl:Restriction;
owl:onProperty a:eats;
owl:allValuesFrom a:Plant
]
).
a:Plant owl:complementOf a:Animal.
a:Sheep rdfs:subClassOf a:Vegetarian.
a:Cow rdfs:subClassOf a:Vegetarian.
a:MadCow
owl:intersectionOf
(a:Cow
[a owl:Restriction;
owl:onProperty a:eats;
owl:someValuesFrom a:Sheep
]
).
a:MadDolly a a:MadCow.

Well, hope this helps any novice in OWL. ;-)

Regards,
Mekan Ikzain

On 9/26/05, Peter F. Patel-Schneider <pfps@research.bell-labs.com> wrote:
>
> One modelling problem in your example is that vegetarians are only
> required to
> eat at least one thing that is a plant. You probably want that everything
> that
> vegetarians eat is derived from plants, although there is a different
> problem
> here for you to spot.
>
> The mad cow example has received a lot of attention. You might want to
> look at
> http://www.mindswap.org/2005/debugging/ for more information. There is as
> well
> a mad cow ontology from Manchester.
>
> Peter F. Patel-Schneider
> Bell Labs Research
>
>
> From: Mekan Ikzain <mekanikzain@gmail.com>
> Subject: Help needed. Isn't this OWL document inconsistent?
> Date: Sun, 25 Sep 2005 23:17:25 +0900
>
> > Hi all,
> >
> > I think the following OWL document is inconsistent,
> > but Pellet says that it's consistent.
> > Please shed some light on my ignorant brain.
> >
> > @prefix rdfs: < http://www.w3.org/2000/01/rdf-schema#
> > <http://www.w3.org/2000/01/rdf-schema#> >.
> > @prefix rdf: < http://www.w3.org/1999/02/22-rdf-syntax-ns#
> > <http://www.w3.org/1999/02/22-rdf-syntax-ns#> >.
> > @prefix owl: < http://www.w3.org/2002/07/owl#
> > <http://www.w3.org/2002/07/owl#> >.
> > @prefix a: < http://www.ex.org/2005/ex# <http://www.ex.org/2005/ex#> >.
> >
> > a:Vegetarian
> > owl:intersectionOf
> > (a:Animal
> > [a owl:Restriction;
> > owl:onProperty a:eats;
> > owl:someValuesFrom a:Plant
> > ]
> > ).
> > a:Plant owl:complementOf a:Animal.
> > a:Sheep rdfs:subClassOf a:Vegetarian.
> > a:Cow rdfs:subClassOf a:Vegetarian.
> > a:MadCow
> > owl:intersectionOf
> > (a:Cow
> > [a owl:Restriction;
> > owl:onProperty a:eats;
> > owl:someValuesFrom a:Sheep
> > ]
> > ).
> >
> > Thanks in advance!
> > Mekan Ikzain
> >
>
Received on Monday, 26 September 2005 11:38:04 GMT

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