Links and attributes not displaying for OWL EL equivalence

Stardog Explorer
1

Hi @Paul_Ambro!

Like I mentioned in the other post, I declared main:Dan as both an instance of main:Man and main:Citizen.

I also declared main:ManCitizen as an intersection of main:Man and main:Citizen.

The main issue is, the explorer is not showing the rdfs:subClassOf relation between main:ManCitizen and the main:Man and main:Citizen classes, even though if I click to see the details of main:ManCitizen or I right-click and navigate to expand node by instances, the knowledge graph is aware that main:Dan is indeed a main:ManCitizen.

Thanks in advance!

Here's the example file:

@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix main: <http://www.example.com/> .
@prefix org: <http://www.w3.org/ns/org#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix so: <https://schema.org/> .
@prefix stardog: <tag:stardog:api:> .
@prefix time: <http://www.w3.org/2006/time#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix : <http://api.stardog.com/> .

<http://www.example.com/> a owl:Ontology .

foaf:gender a owl:DatatypeProperty .

main:Man a owl:Class ;
    rdfs:subClassOf foaf:Person ;
    owl:equivalentClass [
        a owl:Class ;
        owl:intersectionOf ( foaf:Person [
            a owl:Restriction ;
            owl:hasValue "man" ;
            owl:onProperty foaf:gender
        ] )
    ] .

foaf:Person a owl:Class .

main:Dan a main:Citizen , main:Man , owl:NamedIndividual .

main:Citizen a owl:Class ;
    rdfs:subClassOf foaf:Person .

main:ManCitizen a owl:Class ;
    owl:equivalentClass [
        a owl:Class ;
        owl:intersectionOf ( main:Citizen main:Man )
    ] .

And here are some screenshots:

Screenshot
Screenshot3840×2110 335 KB

Screenshot
Screenshot3840×2110 200 KB

Screenshot
Screenshot3840×2110 339 KB

2

Hi Daniel,

At this time, Stardog Explorer supports a limited set of OWL. If developing your data model in Stardog Designer, we will support all Stardog Designer capabilities.

For the latest information on what Explorer supports, please see our documentation.

Thanks,
Laura

3

Hi @Laura_Firey!

Based on the documentation:

“The Model setting is limited to your Stardog Server’s reasoning schemas and allows you to specify a specific reasoning schema. By default, Explorer uses the default reasoning schema.”

And afaik, the default reasoning schema is OWL SL which supports EL and thus supports equivalence axioms.

main:Dan is in fact being inferred as an instance of main:ManCitizen, but only if I expand by instance.

Maybe I’m missing something, but, why is it properly displayed as an instance if I expand, but not being displayed as an instance visually?

Thank you in advance!

4

Hi @Laura_Firey!

The solution discussed over at the "Links and attributes not displaying between classes and their instances" shows that the reasoning is working properly.

  • ex:Dan was declared as a ex:ManCitizen
  • ex:ManCitizen was declared an rdfs:subClassOf ex:Man and ex:Citizen using an equivalence intersection:
ex:ManCitizen a owl:Class ;
    owl:equivalentClass [
        a owl:Class ;
        owl:intersectionOf ( ex:Citizen ex:Man )
    ] .

So, since this doesn't seem to be a reasoning issue, it might be an issue with Explorer itself.

Does Explorer support OWL EL?

If so,

Why is Explorer not showing the rdfs:subClassOf relation between ex:Man and ex:ManCitizen?

Thanks!!

5

Hi,

The "default reasoning schema" actually refers to a named graph within your database [1]. If you're using Stardog 10, that named graph is tag:stardog:api:context:schema (whereas before it defaulted to all local graphs, including the default/no graph). If you load your ontology in there (or somewhere else with an updated reasoning.schema.graphs setting), you should see Explorer reflect it.

6

Hi @stephen!

Thanks for clarifying!

In that case, how could I configure my schema and my OWL profile, so that Explorer shows the inferred equivalence relations I mentioned?

Afaik, OWL SL (the default reasoning profile) supports OWL 2 EL, which in turn supports equivalence inference.

This is also confirmed when performing a SPARQL query in Stardog Studio for an inferred relationship and receiving the expected response.

The issue is present in Stardog Explorer, where the inferred relation is working for detail views, but not showing the arrows for the relationships in the canvas.

Hope this clarifies the issue.

Thanks a lot! :smiley: