User blog comment:Boboris02/MBOT/@comment-1605058-20161220212557/@comment-5529393-20161221171322

Eh, you said that the $$\neg$$ was applied before the $$\iff$$'s that followed, meaning $$n \neg n$$ would be evaluated first.

So I guess $$\neg$$ is not evaluated first.

So what do we look at first? Is it $$n \iff k$$? Are n and k natural numbers, and if so, what does $$ n \iff k$$ mean?