Note
Sometimes mathematics can be very frustrating. After battling with many papers trying to extract some citable theorems, I finally went to get *the* book on the subject from the maths library. Except on arriving, there was a sign up saying it had just closed for the month. I did cry out in the corridor, which led to a kind soul emerging from the coffee room and getting me let in. But then I found the book I was looking for, and it did everything I need, except not quite. And the theorem everyone has been citing doesn't say what it needs to, nor what people say it does.