Propert Property 1: at the level I of binary tree, there are at most 2i-Inodes(i2 1) prove using induction Prove: when i=l, there is only root node,21-1=2 0=1 Provided to all j, i>j21, then proposition is right, that is to say there are at most 2j-Inodes at level j. From Induction hypothesis, we know that there are at most 2i-2nodes at level i-1 Since the degree of every node in binary tree is at most 2. so the maximum node value of level l is as twice as the maximum node value of level i-1 namely 2* 2i-2=2 1-1.Property Property 1: at the level I of binary tree, there are at most 2i-1nodes. (i  1) [prove using induction] Prove: when i=1,there is only root node,2i-1=2 0=1 Provided to all j, i>j1,then proposition is right, that is to say there are at most 2j-1nodes at level j. From Induction hypothesis, we know that there are at most 2i-2nodes at level i-1. Since the degree of every node in binary tree is at most 2, so the maximum node value of level I is as twice as the maximum node value of level i-1, namely 2* 2i －2= 2 i-1