* @param n
   * @param moduleName
   * @param environment
   * @return LogicObject
   */
  public static LogicObject sGetNthDomain(String relationName, int n, String moduleName, Environment environment) {
    { Context module = PLI.safelyGetModule(moduleName, environment);
      Stella_Object relation = PLI.safelyGetRelation(relationName, ((Module)(module)), environment);

      if (relation != null) {
        return (PLI.getNthDomain(((LogicObject)(relation)), n));
      }
      else {
        return (null);
      }
    }
  }