public boolean booleann (String name, String description, 
    boolean default_value) {

    boolean retval = default_value;

    try {
      String opt = option (name);
      if (opt != null && opt.equals ("true")) retval = true;
      if (opt != null && opt.equals ("false")) retval = false;

    } catch (RuntimeException e) {
      invalid_names.append (name + ", ");
      // fall through
    }

    add_spec (name, "boolean", description, 
      String.valueOf (default_value), String.valueOf (retval));
    return retval;
  }