module HL11FAIS where

natpairs = [(x, z - x) | z <- [0 ..], x <- [0 .. z]]

rationals = [(n, m) | (n, m) <- natpairs, m /= 0, gcd n m == 1]

diagonal :: (Integer -> [Bool]) -> Integer -> Bool
diagonal f n = not ((f n) !! (fromInteger n))

f :: Integer -> [Bool]
f 0 = cycle [False]
f (n + 1) = True : f n