[Pellet-users] A simple OWL-DL query

[Wolfgang May]

Hi,

On Tue, 12 Feb 2008, João Paulo Sousa wrote:

> Hi,
> 
> I have the above ontology, basically it's define a person and a  
> location, and the person can have a location.
> 
> In this sample steve is in the bar and bill is in theater, and the bar  
> isPartOf (Transitive property) theater.
> 
> It's possible to make a query to know if steve is in the theater? But  
> using the Transitive property, of course ;-) . How to make this  
> query? :-)

Not really:

for what you want to do, you would need role-chains (OWL 1.1, but 
already supported by Pellet), e.g.
  is-in SubpropertyOf (is-in concat is-part-of).

For demonstrating transitivity of is-part-of, you would
at least need e.g.
  bar is-part-of theaterFirstFloor.
  theater-First-Floor is-part-of theater.

AFAIR, role chains are only allowed with atomic roles, i.e. not with a
transitive one as above. Transitivity alone cannot combine edges
along different roles.

You can probably hack something by defining 
  is-in subPropertyOf myrole.
  is-part-of subPropertyOf myrole.
  myrole a transitiveProperty.
  [I am even not sure that this is allowed]
and ask for
  ?X myrole ?B . ?X a person . ?B a partofbuilding
to select those  x myrole y  that you are interested in.
But that's dirty ;)

Wolfgang


> 
> Cheers,
> 
> João Paulo.
> 
> 
> <?xml version="1.0"?>
> <!DOCTYPE rdf:RDF [
>      <!ENTITY owl "http://www.w3.org/2002/07/owl#" >
>      <!ENTITY xsd "http://www.w3.org/2001/XMLSchema#" >
>      <!ENTITY rdfs "http://www.w3.org/2000/01/rdf-schema#" >
>      <!ENTITY rdf "http://www.w3.org/1999/02/22-rdf-syntax-ns#" >
> ]>
> <rdf:RDF xmlns="http://example.org#"
>       xml:base="http://example.org"
>       xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
>       xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
>       xmlns:owl="http://www.w3.org/2002/07/owl#"
>       xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
>      <owl:Ontology rdf:about=""/>
>      <Room rdf:ID="bar">
>          <isPartOf rdf:resource="#theater"/>
>      </Room>
>      <Person rdf:ID="bill">
>          <hasLocation rdf:resource="#theater"/>
>      </Person>
>      <owl:Class rdf:ID="Building">
>          <rdfs:subClassOf rdf:resource="#Spac"/>
>      </owl:Class>
>      <owl:ObjectProperty rdf:ID="contains">
>          <rdf:type rdf:resource="&owl;TransitiveProperty"/>
>          <rdfs:domain rdf:resource="#Spac"/>
>          <rdfs:range rdf:resource="#Spac"/>
>          <owl:inverseOf rdf:resource="#isPartOf"/>
>      </owl:ObjectProperty>
>      <owl:ObjectProperty rdf:ID="hasLocation">
>          <rdfs:domain rdf:resource="#Person"/>
>          <rdfs:range rdf:resource="#Spac"/>
>      </owl:ObjectProperty>
>      <owl:ObjectProperty rdf:ID="isPartOf">
>          <rdfs:domain rdf:resource="#Spac"/>
>          <rdfs:range rdf:resource="#Spac"/>
>          <owl:inverseOf rdf:resource="#contains"/>
>      </owl:ObjectProperty>
>      <owl:Class rdf:ID="Person"/>
>      <owl:Class rdf:ID="Room">
>          <rdfs:subClassOf rdf:resource="#Spac"/>
>      </owl:Class>
>      <owl:Class rdf:ID="Spac"/>
>      <Person rdf:ID="steve">
>          <hasLocation rdf:resource="#bar"/>
>      </Person>
>      <Building rdf:ID="theater">
>          <contains rdf:resource="#bar"/>
>      </Building>
> </rdf:RDF>
> 
> 
> 
> 
> 
> _______________________________________________
> Pellet-users mailing list
> Pellet-users at lists.owldl.com
> http://lists.owldl.com/mailman/listinfo/pellet-users
> _______________________________________________
> 
> Sponsored by Clark & Parsia, LLC http://clarkparsia.com/
>