Hi,
On 19/07/12 11:18, Olivier Rossel wrote:
Hello all.
I have a small ontology:
<?xml version="1.0"?>
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#";
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#";
xmlns:owl="http://www.w3.org/2002/07/owl#"; >
<owl:Class rdf:about="http://dbpedia.org/class/yago/Album106591815"/>
<owl:Class
rdf:about="http://dbpedia.org/class/yago/HostCitiesOfTheCommonwealthGames"/>
<owl:ObjectProperty rdf:about="http://dbpedia.org/property/after";>
<rdfs:domain>
<owl:Class>
<owl:unionOf rdf:parseType="Collection">
<owl:Class rdf:about="http://dbpedia.org/class/yago/Album106591815"/>
</owl:unionOf>
</owl:Class>
</rdfs:domain>
</owl:ObjectProperty>
</rdf:RDF>
that I load in a Jena OntModel with OntSpec set to OWL_MEM_MICRO_RULE_INF .
When I ask Jena to listHierarchyRootClasses(), I get only
HostCitiesOfTheCommonwealthGames.
If I change my ontology so the unionOf contains
HostCitiesOfTheCommonwealthGames instead of Album106591815,
and I ask Jena to listHierarchyRootClasses(), then I get only Album106591815.
Is there something wrong in my modeling? Or is OWL_MEM_MICRO_RULE_INF
too limited to manage my ontology?
Neither, it's a combination of how you are printing things and Jena's
RDF-centric view of the world.
From an RDF point of view the anonymous union class you are creating is
a perfectly valid class and so counts as a hiearchyRoot. So your above
example has the class structure:
> HostCitiesOfTheCommonwealthGames
> _:1 > Album106591815
where _:1 is meant to represent the anonymous class.
When I run listHierarchyRootClasses (with OWL_MEM_MICRO_RULE_INF) on
your data then in fact I see two classes listed, one bNode and
HostCitiesOfTheCommonwealthGames.
Dave
