def add(m, n): if m == 0: return n if n == 0: return m return add(m-1, succ(n))

is a recursive function. (Note that this function is similar to the one in the [previous example](#adding-two-numbers).)


### Exercise 3 - Recursive Definition of Multiplication

The `mult` function takes two numbers as arguments and returns the result of multiplying the two numbers.

This function is already defined in the code below.

Please study the comments in the code and then complete the exercise.

This exercise can be completed by answering the questions in the [exercise notebook](https://github.com/ml-classroom/recursion-workshop/blob/master/exercise-notebooks/exercise3.ipynb). 

You can run the code below by clicking the "Run" button above.

#### Exercise 3 - Code

You can run the code below by clicking the "Run" button above.