# CS 173: Skills list for Examlet 7

- Recursively-defined sets
- Given a recursive definition of a set, create a non-recursive definition, and vice versa.
- Identify which elements are / are not in a recursively defined set.

- Recursively-defined functions
- Evaluate a given recursively defined function on given values.
- Define a function recursively meeting a given specification.
- Identify invalid recursive function definitions.

- Structural induction
- Prove properties of recursively-defined sets and recursively-defined functions using structural induction.