If x != 0, then 1/(1/x) = x.

I know by m5 you can rewrite as:

$\displaystyle 1/(x^{-1})$ = x.

Im not quite sure how to proceed here however, I thought using m2 would help for this, but im not sure how I should show that $\displaystyle \frac1{x^{-1}}$$\displaystyle (x)$ = $\displaystyle x^{2}$