GIve a formal proof or derivation of:
(a iff (b iff c)) iff ((a iff b) iff c))
The Attempt at a Solution
I've tried it for a long time. Idea is to assume (a iff (b iff c)) then get ((a iff b) iff c)) and then vice versa. BUt no matter how I try, I always get some if conditions istead of the iff.