public static Cons updateProposition(Stella_Object tree, Keyword updatemode) {
    try {
      { Object old$InhibitobjectfinalizationP$000 = Logic.$INHIBITOBJECTFINALIZATIONp$.get();

        try {
          Native.setBooleanSpecial(Logic.$INHIBITOBJECTFINALIZATIONp$, true);
          return (Logic.updateTopLevelProposition(Logic.standardizePropositionTree(tree), updatemode));

        } finally {
          Logic.$INHIBITOBJECTFINALIZATIONp$.set(old$InhibitobjectfinalizationP$000);
        }
      }
    } catch (LogicException e) {
      Stella.STANDARD_ERROR.nativeStream.print(Stella.exceptionMessage(e));
    } catch (ReadException e) {
      Stella.STANDARD_ERROR.nativeStream.print(Stella.exceptionMessage(e));
    }
    return (null);
  }