Posted: Sep 14, 2015 2:11 pm
ED209 wrote:Anyway back to the OP, christ on a bike - diagonalisation trivially shows that rational numbers are indeed countable, and how to count them. It's the sort of thing you might show a primary school child to teach them that maths isn't just about increasingly difficult sums, but about solving prolems by approaching them in different ways.
How can such an error possibly make it onto an exam paper? Who would think that, and how the fuck did they find themselves writing maths exams using only their ignorant and wrong intuitions?
Perhaps you should be asking what group in the US has a stake in the notion that "actual infinities are impossible".