*
   * @throws IOException if a data communication error occurs
   * @throws CycApiException if the api request results in a cyc server error
   */
  public int getArity(CycFort predicate)
          throws IOException, CycApiException {
    String command = makeSubLStmt(WITH_ALL_MTS,
            makeNestedSubLStmt("arity", predicate));
    Object object = this.converseObject(command);
    if (object instanceof Integer) {
      return (Integer) object;
    } else {
      return 0;
    }
  }