测试两棵树是否相等并在Haskell中对树进行二进制搜索

data Tree a = Empty | Node a (Tree a) (Tree a)

isEqual :: Eq a => Tree a -> Tree a -> Bool
isEqual Empty Empty = True
isEqual (Node x left1 right1) (Node y left2 right2) =
  x == y && isEqual left1 left2 && isEqual right1 right2
isEqual _ _ = False

binarySearch :: Ord a => Tree a -> a -> Bool
binarySearch Empty _ = False
binarySearch (Node x left right) value
  | value == x = True
  | value < x = binarySearch left value
  | otherwise = binarySearch right value