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

      if (relation != null) {
        return (PLI.getArity(((LogicObject)(relation))));
      }
      else {
        return (Stella.NULL_INTEGER);
      }
    }
  }