* @return boolean
   */
  public static boolean unknownP(Proposition self) {
    { TruthValue tv = ((TruthValue)(Stella_Object.accessInContext(self.truthValue, self.homeContext, false)));

      return (((tv == Logic.UNKNOWN_TRUTH_VALUE) ||
          (tv == null)) ||
          (((!(!((Boolean)(Logic.$DONTUSEDEFAULTKNOWLEDGEp$.get())).booleanValue())) &&
          ((tv == Logic.DEFAULT_TRUE_TRUTH_VALUE) ||
           (tv == Logic.DEFAULT_FALSE_TRUTH_VALUE))) ||
           (tv == Logic.INCONSISTENT_TRUTH_VALUE)));
    }
  }