4 files changed, 24 insertions, 11 deletions

diff --git a/src/main/scala/uk/ac/ox/cs/rsacomb/CanonicalModel.scala b/src/main/scala/uk/ac/ox/cs/rsacomb/CanonicalModel.scala
index c605e51..5001c8a 100644
--- a/src/main/scala/uk/ac/ox/cs/rsacomb/CanonicalModel.scala
+++ b/src/main/scala/uk/ac/ox/cs/rsacomb/CanonicalModel.scala
@@ -247,11 +247,10 @@ class CanonicalModel(val ontology: RSAOntology) {
         }
 
         case a: OWLSubObjectPropertyOfAxiom => {
-          val (factsF, rulesF) =
-            super.convert(a, term, unsafe, NoSkolem, Forward)
-          val (factsB, rulesB) =
-            super.convert(a, term, unsafe, NoSkolem, Backward)
-          (factsF ::: factsB, rulesF ::: rulesB)
+          val (facts, rules) = List(Empty, Forward, Backward)
+            .map(super.convert(a, term, unsafe, NoSkolem, _))
+            .unzip
+          (facts.flatten, rules.flatten)
         }
 
         case a => super.convert(a, term, unsafe, skolem, suffix)
diff --git a/src/main/scala/uk/ac/ox/cs/rsacomb/RSAOntology.scala b/src/main/scala/uk/ac/ox/cs/rsacomb/RSAOntology.scala
index 79f2ef3..dc64c79 100644
--- a/src/main/scala/uk/ac/ox/cs/rsacomb/RSAOntology.scala
+++ b/src/main/scala/uk/ac/ox/cs/rsacomb/RSAOntology.scala
@@ -11,6 +11,7 @@ import org.semanticweb.owlapi.model.{OWLOntology, OWLAxiom, OWLLogicalAxiom}
 import org.semanticweb.owlapi.model.{
   OWLClass,
   OWLClassExpression,
+  OWLDataPropertyAssertionAxiom,
   OWLObjectProperty,
   OWLSubObjectPropertyOfAxiom,
   OWLObjectPropertyExpression,
@@ -35,7 +36,8 @@ import tech.oxfordsemantic.jrdfox.logic.expression.{
   Term,
   Variable,
   IRI,
-  Resource
+  Resource,
+  Literal
 }
 import tech.oxfordsemantic.jrdfox.logic.sparql.statement.SelectQuery
 
@@ -122,6 +124,12 @@ class RSAOntology(val ontology: OWLOntology) {
       .map(implicits.RDFox.owlapiToRdfoxIri)
       .toList
 
+  val literals: List[Literal] =
+    abox
+      .collect { case a: OWLDataPropertyAssertionAxiom => a }
+      .map(_.getObject)
+      .map(implicits.RDFox.owlapiToRdfoxLiteral)
+
   val concepts: List[OWLClass] =
     ontology.getClassesInSignature().asScala.toList
 
@@ -298,7 +306,7 @@ class RSAOntology(val ontology: OWLOntology) {
 
   def filteringProgram(query: ConjunctiveQuery): FilteringProgram =
     Logger.timed(
-      new FilteringProgram(query, individuals),
+      new FilteringProgram(query, individuals ++ literals),
       "Generating filtering program",
       Logger.DEBUG
     )
diff --git a/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxConverter.scala b/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxConverter.scala
index 6c83caf..6193296 100644
--- a/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxConverter.scala
+++ b/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxConverter.scala
@@ -225,7 +225,7 @@ trait RDFoxConverter {
         * @see [[org.semanticweb.owlapi.model.OWLDataPropertyAssertionAxiom OWLDataPropertyAssertionAxiom]]
         */
       case a: OWLDataPropertyAssertionAxiom =>
-        if (!a.getSubject.isNamed || !a.getObject.isNamed)
+        if (!a.getSubject.isNamed)
           Result()
         else {
           val subj = a.getSubject.asOWLNamedIndividual.getIRI
diff --git a/src/main/scala/uk/ac/ox/cs/rsacomb/sparql/ConjunctiveQueryAnswers.scala b/src/main/scala/uk/ac/ox/cs/rsacomb/sparql/ConjunctiveQueryAnswers.scala
index 50cbb86..667defc 100644
--- a/src/main/scala/uk/ac/ox/cs/rsacomb/sparql/ConjunctiveQueryAnswers.scala
+++ b/src/main/scala/uk/ac/ox/cs/rsacomb/sparql/ConjunctiveQueryAnswers.scala
@@ -1,6 +1,11 @@
 package uk.ac.ox.cs.rsacomb.sparql
 
-import tech.oxfordsemantic.jrdfox.logic.expression.{IRI, Resource, Variable}
+import tech.oxfordsemantic.jrdfox.logic.expression.{
+  IRI,
+  Literal,
+  Resource,
+  Variable
+}
 
 /** A collections of answers to a query.
   *
@@ -30,8 +35,9 @@ class ConjunctiveQueryAnswers(
         val header = variables map (_.getName) mkString "\t"
         val body = answers
           .map(_.map {
-            case x: IRI => x.getIRI
-            case x      => x.toString
+            case x: IRI     => x.getIRI
+            case x: Literal => x.getLexicalForm
+            case x          => x.toString
           }.mkString("\t"))
           .mkString("\n")
         s"$header\n$body"