db);
  });
  D = (function (db)
  {
    if ((db.Tag == 1.000000)) 
    {
      var eb = db.Item2;
      var fb = db.Item1;
      return fb;
    }
    else
    {
      throw ("List was empty");
      return null;
    };
  });
  E = (function (db)
  {
    return a((function (eb)
    {
      return (function (fb)
      {
        return (new ab(eb, fb));
      });
    }), db, (new bb()));
  });
  F = (function (db)
  {
    return z((function (eb)
    {
      return (function (fb)
      {
        return (new ab(