findLeafB :: (Ord a) => a -> BlackZip a n -> BlackZip a Z
findLeafB u z@(LeafZip c) = z
findLeafB :: (Ord a) => a -> BlackZip a n -> BlackZip a Z
findLeafB u z@(LeafZip c) = z
findLeafB u z@(LeafZip c) = z