code: @Override
      public void addDisjointClassesAxiom(ClassExpression... ces) throws InconsistentOntologyException {
          for (ClassExpression c : ces)
              checkSignature(c);
          classAxioms.addDisjointness(ces);
      }
docs: Normalizes and adds class disjointness axiom
  <p>
  DisjointClasses := 'DisjointClasses' '(' axiomAnnotations
  subClassExpression subClassExpression { subClassExpression } ')'<br>
  <p>
  Implements rule [C2]:<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)