Let `f: W ->W`be defined as `f(n) = n - 1`, if `n` is odd and `f(n) = n + 1`, if `n` is even. Show that `f` is invertible. Find the inverse of `f`. Here, `W` is the set of all whole numbers.

Explanation

To solve the problem, we need to show that the function \( f: W \to W \) defined by:

\[
f(n) =
\begin{cases}
n - 1 & \text{if } n \text{ is odd} \\
n + 1 & \text{if } n \text{ is even}
\end{cases}
...