isEven :: Integer -> Bool
isEven n
  | n `mod` 2 == 0 = True
  | otherwise      = False
isEven :: Integer -> Bool
isEven n
  | n `mod` 2 == 0 = True
  | otherwise      = False
isEven n
  | n `mod` 2 == 0 = True
  | otherwise      = False