Kata

Mutual Recursion allows us to take the fun of regular recursion (where a function calls itself until a terminating condition) and apply it to multiple functions calling each other!

Let's use the Hofstadter Female and Male sequences to demonstrate this technique. You'll want to create two functions F and M such that the following equations are true:

F(0) = 1
M(0) = 0
F(n) = n - M(F(n - 1))
M(n) = n - F(M(n - 1))

Don't worry about negative numbers, n will always be greater than or equal to zero.

Hofstadter Wikipedia Reference http://en.wikipedia.org/wiki/Hofstadter_sequence#Hofstadter_Female_and_Male_sequences