Add generic Ontology wrapper for common tasks

1 files changed, 90 insertions, 0 deletions

diff --git a/src/main/scala/uk/ac/ox/cs/rsacomb/ontologies/Ontology.scala b/src/main/scala/uk/ac/ox/cs/rsacomb/ontologies/Ontology.scala
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+++ b/src/main/scala/uk/ac/ox/cs/rsacomb/ontologies/Ontology.scala
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+/*
+ * Copyright 2020, 2021 KRR Oxford
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package uk.ac.ox.cs.rsacomb.ontology
+
+import java.io.File
+
+import org.semanticweb.owlapi.apibinding.OWLManager
+import org.semanticweb.owlapi.model.{OWLOntology, OWLAxiom, OWLLogicalAxiom}
+import org.semanticweb.owlapi.model.{OWLObjectPropertyExpression}
+import org.semanticweb.owlapi.reasoner.structural.StructuralReasonerFactory
+
+object Ontology {
+
+  /** Manager instance to interface with OWLAPI */
+  val manager = OWLManager.createOWLOntologyManager()
+  //val factory = manager.getOWLDataFactory()
+
+}
+
+/** A wrapper for
+  */
+class Ontology(val axioms: List[OWLLogicalAxiom], val datafiles: List[File]) {
+
+  /** Extend OWLAxiom functionalities */
+  import uk.ac.ox.cs.rsacomb.implicits.RSAAxiom._
+
+  /** OWLOntology based on input axioms */
+  private val ontology: OWLOntology =
+    Ontology.manager.createOntology((axioms: List[OWLAxiom]).asJava)
+
+  /** OWLAPI internal reasoner for ontology */
+  private val reasoner =
+    (new StructuralReasonerFactory()).createReasoner(ontology)
+
+  /** Unsafe roles in the ontology
+    *
+    * Unsafety conditions are the following:
+    *
+    * 1) For all roles r1 appearing in an axiom of type T5, r1 is unsafe
+    *    if there exists a role r2 (different from top) appearing in an
+    *    axiom of type T3 and r1 is a subproperty of the inverse of r2.
+    *
+    * 2) For all roles p1 appearing in an axiom of type T5, p1 is unsafe
+    *    if there exists a role p2 appearing in an axiom of type T4 and
+    *    p1 is a subproperty of either p2 or the inverse of p2.
+    */
+  lazy val unsafe: List[OWLObjectPropertyExpression] = {
+
+    /* Checking for unsafety condition (1) */
+    val unsafe1 = for {
+      axiom <- axioms
+      if axiom.isT5
+      role1 <- axiom.objectPropertyExpressionsInSignature
+      roleSuper = role1 +: reasoner.superObjectProperties(role1)
+      axiom <- axioms
+      if axiom.isT3 && !axiom.isT3top
+      role2 <- axiom.objectPropertyExpressionsInSignature
+      if roleSuper contains role2.getInverseProperty
+    } yield role1
+
+    /* Checking for unsafety condition (2) */
+    val unsafe2 = for {
+      axiom <- axioms
+      if axiom.isT5
+      role1 <- axiom.objectPropertyExpressionsInSignature
+      roleSuper = role1 +: reasoner.superObjectProperties(role1)
+      axiom <- axioms
+      if axiom.isT4
+      role2 <- axiom.objectPropertyExpressionsInSignature
+      if roleSuper.contains(role2) ||
+        roleSuper.contains(role2.getInverseProperty)
+    } yield role1
+
+    unsafe1 ++ unsafe2
+  }
+}