TITLE: How to write $X \iff Y$ in CNF form?
QUESTION [5 upvotes]: I know that $X \iff Y$ is true when

$X$ is True and $Y$ is True
$X$ is False and $Y$ is False

I know that there is a simple algorithm to convert to CNF form, but I don't remember it...

REPLY [3 votes]: $(\neg X \vee Y)\wedge(X\vee\neg Y)$