setSameAs() Linked Data --- Jena

Question

I am trying to link two individuals A and B using

      B.setSameAs(A) OR A.setSameAs(B)

A has properties hasOne, hasTwo

B has a property hasThree

and I'm hoping that the property of B can be inferred as a property of A. Unfortunately, when I list A's properties, hasThree doesn't appear

This is my setup:

      OntModel onto = ModelFactory.createOntologyModel(OntModelSpec.OWL_MEM_MICRO_RULE_INF, null);

      String NAMESPACE1 = "http://mynamespace.one#";
      String NAMESPACE2 = "http://mynamespace.two#";

      OntClass myClass = onto.createClass(NAMESPACE1 + "MyClass");

      Individual a = onto.createIndividual(NAMESPACE1 + "A", myClass);
      Individual b = onto.createIndividual(NAMESPACE2 + "B", myClass);

NOTE: I used a different namespace for B to simulate a different address, but in this setup it is using the same class type

      OntProperty one = onto.createOntProperty(NAMESPACE1 + "hasOne");
      OntProperty two = onto.createOntProperty(NAMESPACE1 + "hasTwo");
      OntProperty three = onto.createOntProperty(NAMESPACE2 + "hasThree");

NOTE: the hasThree property is located in the same address of B

      a.setLiteral(one, true);
      a.setLiteral(two, true);
      b.setLiteral(three, true);

      a.setSameAs(b);          //THIS results in the RDF entry for A to have a line <owl:sameAs rdf:resource:"http://mynamespace.two#B" />
      //b.setSameAs(a);          //I TRIED using this too, but it didn't work either

      // IN HERE I JUST SET AN ITERATOR TO SHOW ALL OF THE PROPERTIES OF A
      // UNFORTUNATELY, hasThree DOESN'T SHOW UP UNDER THE PROPERTIES OF A

I have itemized the things that are troubling me.

1. When I try to list all of A's properties, hasThree doesn't show up.
2. When I list all individuals of MyClass, both A and B shows up -- I suppose this isn't the correct result since A=B and B=A, so only 1 individual should be displayed.

Answer 1

You aren't using a reasoning profile that supports owl:sameAs

In the OWL Reasoning of the Jena documentation there is a table which lists the OWL coverage of the different reasoner profiles.

The row for owl:sameAs states the following:

owl:sameAs, owl:differentFrom, owl:distinctMembers  | full, mini  | owl:distinctMembers is currently translated into a quadratic set of owl:differentFrom assertions.

So in order to get the behaviour you desire you must be using a Full/Mini OWL reasoner, your code shows you are using the Micro reasoner.

Changing your code to use OntModelSpec.OWL_MEM_MINI_RULE_INF instead should solve your problem.