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.
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