A most decidedly curious yet important theorem for mathematics and other fields…
Lemma: Infinity is both an even and an odd number.
Proof: 2(∞) =∞. Therefore ∞ is even. If ∞ is even then ∞ + 1 is odd. But ∞ + 1 = ∞. Therefore ∞ is both even and odd.
Lemma: ∞ is the only number that is both even and odd.
Proof: The proof is left as an exercise for the reader.
Alexander the Great had an infinite number of limbs.
Proof: Alexander the great had two arms and two legs. 2 + 2 = 4 is an even number. Thus Alexander had an even number of limbs. Once when Alexander was on a military campaign, he was about to cross a river when a seer jumped from a wood in front of the great warrior. The seer said, “Alexander, if you cross this river you will die”.
Now fore warned is fore armed, and two legs and four arms make six limbs. This is certainly an odd number of limbs to have. Since Alexander had both and odd and an even number of limbs, and there is only one number with that property, Alexander had an infinite number of limbs. QED.
Note: You might also enjoy Quirky Joke: The Indian Mathematician