[bmelton]

If you had an infinitely long rope and access to an infinitely deep chasm, then there's no reason it wouldn't be considered a perpetual motion machine.

[kevinh]

With an infinitely long rope and an infinitely deep chasm there would not be substantial gravity pulling it downward to have perpetual motion.

[rtkwe]

No gravity would simply approach infinity as you descended the well. And since we're being pedantic that's not an issue.