[Pellet-users] getting individuals

[Bijan Parsia]

On Friday, July 25, 2008 8:36am, "Alexander Becker" <trennung at weinenvorglueck.de> said:

> Hi all.
> 
> I'm sorry that Ihave to ask nearly the same thing over and over, but it just won't
> work.
> 
> I have an ontology, that consists of some rdfs, that load some owls. Ther is 1 owl
> file, that contains all properties that were used in the whole ontology. It's
> called system.owl.
> 
> Now I want to fetch all individuals that satisfy some properties.

You mean that they must have such a property in every model?

> To satisfy a
> property, an individual must have that property. It's absolutely not relevant what
> value it has.

Ok.

> So:
> - there exists a property named hasTag
> - there exists an individual named NN that has a property hasTag
> - the hasTag property of the individual NN is a subclass of system.owl#hasTag
> 
> How do I get that individual? 

Why not retrieve the instances of (system.owl#hasTag some owl:Thing)?

>I don't know where the individual is located. There
> are about 6 different owl files thatcontains thousands of individuals. As I cannot
> access the list of loaded owl files through the reasoner or the ontology, I cannot
> simply iterate over all these owl files and ask the reasoner for instances that
> satisfy "owl_file#hasTag".
> 
> I thought it would be possible to ask the reasoner for all individuals, that have
> a property that is a subproperty of some property in system.owl.
> Isn't it?

You can do this directly in OWL. If you have protege4, go to the DLQuery tab and enter a (correct) variant of what I wrote above.

Cheers,
Bijan.