Hi :)

I'm trying to prove that

The way I see it, the inverse of is itself, and from to , the inverses are paired up, so we are left with the inverse of which is itself.

So, we have that

My problem (with this proof) is in showing that the inverses are all paired up from to .

a) Is there a way to prove/show this?

or

b) Is there another way to prove ?