Not a disproof or a revelation of my sloppiness either, Grisha, though I admit to quite a bit of sloppiness in my postings in general, and indeed put in a correction to the definition of equality on this thread precisely because of a sloppiness on my first attempt. It is difficult to avoid pendantry in maths precisely because being exact is important, so I do plead guilty with mitigating circumstances on that one. Rapparee pointed out with some subtlety why Misha's disproof wasn't - think about his post a little more