Added test for ForwardRuleReasonerOWLHorst O2 rule

Author: patrickwestphal

sansa-inference-spark/src/test/resources/forward_chaining/axioms/test_o2.owl

@@ -0,0 +1,22 @@
+Prefix(:=<http://ex.com/default#>)
+
+Ontology(<http://ex.com/ont/sample1.owl>
+  <http://ex.com/ont/release/123/sample1.owl>
+
+  Declaration(ObjectProperty(:objProp01))
+  Declaration(ObjectProperty(:objProp02))
+
+  InverseFunctionalObjectProperty(:objProp01)
+
+  Declaration(NamedIndividual(:indivA))
+  Declaration(NamedIndividual(:indivB))
+  Declaration(NamedIndividual(:indivC))
+  Declaration(NamedIndividual(:indivD))
+  Declaration(NamedIndividual(:indivE))
+  Declaration(NamedIndividual(:indivF))
+
+  ObjectPropertyAssertion(:objProp01 :indivA :indivB)
+  ObjectPropertyAssertion(:objProp01 :indivC :indivB)
+  ObjectPropertyAssertion(:objProp01 :indivD :indivB)
+  ObjectPropertyAssertion(:objProp02 :indivE :indivF)
+)

sansa-inference-spark/src/test/scala/net/sansa_stack/inference/spark/forwardchaining/axioms/ForwardRuleReasonerOWLHorstTest.scala

@@ -310,4 +310,48 @@ class ForwardRuleReasonerOWLHorstTest extends FunSuite with SharedSparkContext w
       case _ => assert(false)
     }
   }
+
+  /**
+    * O2:
+    *   Condition:
+    *     p rdf:type owl:InverseFunctionalProperty
+    *     v p u
+    *     w p u
+    *   Consequence:
+    *     v owl:sameAs w
+    */
+  test("Rule O2 should return correct results") {
+    val indivA = df.getOWLNamedIndividual(defaultPrefix + "indivA")
+    val indivC = df.getOWLNamedIndividual(defaultPrefix + "indivC")
+    val indivD = df.getOWLNamedIndividual(defaultPrefix + "indivD")
+
+    val input = getClass.getResource(resourcePath + "test_o2.owl").getPath
+
+    val axiomsRDD = spark.owl(Syntax.FUNCTIONAL)(input)
+    val reasoner = new ForwardRuleReasonerOWLHorst(sc, sc.defaultMinPartitions)
+    val inferred: Seq[OWLAxiom] = reasoner.apply(axiomsRDD).collect()
+
+    // It should be either one axiom inferred:
+    //   SameIndividual(:indivA :indivC :indivD)
+    // or three pairwise axioms:
+    //   SameIndividual(:indivA :indivC)
+    //   SameIndividual(:indivA :indivD)
+    //   SameIndividual(:indivC :indivD)
+    // (where the individual operand pairs may be in arbitrary order)
+    // Permutations are assumed to be handled by the axiom's equals method.
+    inferred.size match {
+      case 1 => assert(
+        inferred.contains(
+          df.getOWLSameIndividualAxiom(Seq(indivA, indivC, indivD).asJava)))
+      case 3 =>
+        assert( // B == C
+          inferred.contains(df.getOWLSameIndividualAxiom(indivA, indivC)))
+        assert( // B == D
+          inferred.contains(df.getOWLSameIndividualAxiom(indivA, indivD)))
+        assert(  // C == D
+          inferred.contains(df.getOWLSameIndividualAxiom(indivC, indivD))
+        )
+      case _ => assert(false)
+    }
+  }
 }