if (n.f1.present()) {
final List<String> operators = new ArrayList<String>();
final List<String> operands = new ArrayList<String>();
for (final Node node : n.f1.nodes) {
final NodeSequence nodeSequence = (NodeSequence) node;
operators.add(((NodeToken) ((NodeChoice) nodeSequence.elementAt(0)).choice).tokenImage);
operands.add(nodeSequence.elementAt(1).accept(this, argu));
}
st.setAttribute("operators", operators);
st.setAttribute("operands", operands);
}