Comment by ziofill

Tangent, but interesting: how do you get fair samples from a biased coin? 1. You take a string of biased samples like 001011100101 2. you split it in pairs 00 10 11 10 01 01 3. you keep only pairs with a zero and a one in them 10 10 01 01 4. You assign 0 and 1 to them, e.g. 1 1 0 0, this is a fair sampling from an unbiased coin

Why does it work? Because even if p(0) ≠ p(1), p(01) = p(10).