1. 12.2-4 Suppose that the search for a key k in a BST ends at a leaf. Consider 3 sets: A the keys to the left of the path, B the keys on the path, and C the keys to the right of the path. Claim: for any $a\in A$, $b\in B$. $c\in C$ $a\leq b\leq c$. Give a smallest possible counterexample
2. 12.3-5 Is deletion commutative. I.e. does deleting x than y always give the same tree as deleting y then x?
3. 13.1-6 What is the largest number of internal nodes in a red-black tree with black-height k? The smallest number?
4. 13.1-8 Argue that in a red-black tree a red node cannot have exactly one non-nil child.
5. 13.4-1 Show that if node y in RB-delete is red then no black-heights change.
Bonus. 13.2-5 Right conversion using Right-Rotate