[JZumun]

It's like a recursive function, where you resolve to stop interfering with the lower universe once the upper universe stops interfering with you. You run it N times until nothing happens in your universe. That means you're N universes deep in the stack.

If you run the program once and not observe anything happening, that means you know you're top level. Then you resolve to not rerun the program.

If you run the program once and observe the black sphere, then run it again and not see the black sphere, you know you're level 2. You resolve to not rerun the program. And on it goes.

EDIT: box to sphere.

[varajelle]

But nothing says the function is ran only only once... There could be someone in the next room also emulating an universe, and not intervening. Or they could emulate the universe 5 minutes later and say "this time we dont intervene"