> [...] then any([]) must be false (otherwise x and y would never matter), and all([]) must be true.

Yes, I know. My problem is with:

> Another reason we must have `all([]) == True`, because `any([])` should obviously be `False`.

Argument is of the form 'A, because B'. But I don't see how B is any more obvious than A here. They seem about equally obvious.