figure recursive definition of tree by an edge figure illustrates this recursive definition of tree using the recursive definition of treewe know that the tree in figure has at least four nodessince each of the triangles representing subtree must have root it may have many more nodes than thatbut we do not know unless we look deeper into the tree implementation keeping in mind the definitions from the previous sectionwe can use the following functions to create and manipulate binary treebinarytree(creates new instance of binary tree get_left_child(returns the binary tree corresponding to the left child of the current node get_right_child(returns the binary tree corresponding to the right child of the current node set_root_val(valstores the object in parameter val in the current node get_root_val(returns the object stored in the current node insert_left(valcreates new binary tree and installs it as the left child of the current node insert_right(valcreates new binary tree and installs it as the right child of the current node the key decision in implementing tree is choosing good internal storage technique python allows us two very interesting possibilitiesso we will examine both before choosing one the first technique we will call "list of lists,the second technique we will call "nodes and references trees and tree algorithms