REXClassExpressionImpl getREXLiteral(OWLLiteral literal) {
		// TODO Auto-generated method stub
		REXLiteralImpl newclazz = literals.get(literal);
		if(newclazz == null)
		{
			newclazz = new REXLiteralImpl(literal);
			newclazz.original = false;
			REXClassExpressionImpl type = getREXDataRange(literal.getDatatype());
			newclazz.superClasses.add(type);
			newclazz.addOriginalSuperClasses(type);
			literals.put(literal, newclazz);
			//			classExpressions.add(newclazz);
		}
		return newclazz;
	}