Need to prove 1) optimal substructure and 2) greedy choice property.

The proof of 2 typically involves:

- a.
- Consider globally-optimal solution.
- b.
- Show greedy choice at first step reduces problem to the same but
smaller problem.

Greedy choice must be- Part of an optimal solution, and
- Can be made first

- c.
- Use induction to show greedy choice is best at each step (i.e., optimal substructure)