Given a proper binary tree T, define the reflection of T to be the binary tree T′ such that each node v in T is also in T′, but the left child of v in T is v’s right child in T′ and the right child of v in T is v’s left child in T′. Show that a preorder traversal of a proper binary tree T is the same as the postorder traversal of T’s reflection, but in reverse order.