code: @Override
      public void addDisjointDataPropertiesAxiom(DataPropertyExpression... dpes) throws InconsistentOntologyException {
          for (DataPropertyExpression dpe : dpes)
              checkSignature(dpe);
          dataPropertyAxioms.addDisjointness(dpes);
      }
docs: Normalizes and adds data property disjointness axiom
  <p>
  DisjointDataProperties := 'DisjointDataProperties' '(' axiomAnnotations
  DataPropertyExpression DataPropertyExpression { DataPropertyExpression } ')'<br>
  <p>
  Implements rule [D2]:<br>
  - eliminates all occurrences of bot and if the result contains<br>
  - no top and at least two elements then disjointness<br>
  - one top then emptiness of all other elements<br>
  - two tops then inconsistency (this behavior is an extension of OWL 2, where duplicates are removed from the list)