@Override
  public CheckTypesResult checkExprTypeBounds() {
    CheckTypesResult result = new CheckTypesResult();
    result.addMinTypeExprent(index, VarType.VARTYPE_BYTECHAR);
    result.addMaxTypeExprent(index, VarType.VARTYPE_INT);
    return result;
  }
@Override
  public CheckTypesResult checkExprTypeBounds()