Py3 Sol: in just few lines, 24ms, beats 97.63%
\ndef isSymmetricBst(node1, node2):\n    if node1==None and node2==None:\n        return True\n    elif node1==None or node2==None:\n        return False\n    e
```\ndef isSymmetricBst(node1, node2):\n    if node1==None and node2==None:\n        return True\n    elif node1==None or node2==None:\n        return False\n    else:\n        return node1.val==node2.val and isSymmetricBst(node1.left,node2.right) and isSymmetricBst(node1.right, node2.left)\n    \nclass Solution:\n    def isSymmetric(self, root: TreeNode) -> bool:\n        if not root:\n            return True\n#         since we need to check whether left is mirror to right, vice versa\n        return isSymmetricBst(root.left, root.right)\n```
['Python', 'Python3']