+ is a map from N×N to N where a + 0 = a and a + S(b) = S(a + b) (S is the successor function that gives the next number).
Then 1 + 1 = 1 + S(0) = S(1 + 0) = S(1) = 2.
EDIT: I see that the “fediverse” link for posts has been removed.
It's still there, just not when the post/comment comes from the instance you're on. Even though the post is to a lemmy.ml community, it's from lemmy.world so that's where the fediverse link goes to.
I'm surprised from the other side, there's always people defending deepfake porn on Lemmy