## A Christmas Theorem

**Theorem.**
Santa Claus exists.

**Proof.**
Let be the sentence "If then Santa Claus exists." This looks a bit self-referential but actually such a sentence, or an equivalent one, is constructible by the Diagonalisation Lemma.

Now, is of the form where (the antecedent) is just and (the consequent) is "Santa Claus exists." So of course if we assume and show that is true, then we have showed . Hence assume . Hence (by ) Santa Claus exists. But this was the consequent. Hence . Hence Santa Claus exists.

**Corollary.**
Merry Christmas!

**Related tags:**
christmas
humour
maths
theorem

## Comments

## John Doe

said at 8:03 p.m. on 22. December, 2013 (4 years ago)Math nerds D:

## Can better posture make you taller?

said at 5:51 a.m. on 22. July, 2017 (2 months ago)Thanks a lot for sharing this with all people you actually recognize what you're speaking

approximately! Bookmarked. Kindly additionally talk over with

my website =). We could have a hyperlink change arrangement between us