Using the Axiom of Choice and partial transfiguration, Harry divides himself into two exact copies, one of which is killed by the Death Eaters and the other of which escapes.
If you can tell me exactly how to do something, Harry is allowed to think of it. But it does not serve as a solution to say, for example, “Harry should persuade Voldemort to let him out of the box” if you can’t yourself figure out how.
Mathematical progress ground to a standstill in March of 2015, when thousands of researches abandoned their work to search for a constructive proof of the Banach–Tarski theorem.
(Not a serious suggestion)
Using the Axiom of Choice and partial transfiguration, Harry divides himself into two exact copies, one of which is killed by the Death Eaters and the other of which escapes.
Mathematical progress ground to a standstill in March of 2015, when thousands of researches abandoned their work to search for a constructive proof of the Banach–Tarski theorem.
It’s a little vague how to define ‘constructive’, but we pretty much already know that there isn’t one. https://en.wikipedia.org/wiki/Solovay_model