Lemma Jokes / Recent Jokes

Prove that the crocodile is longer than it is wide. Lemma 1. The crocodile is longer than it is green: Let's look at the crocodile. It is long on the top and on the bottom, but it is green only on the top. Therefore, the crocodile is longer than it is green. Lemma 2. The crocodile is greener than it is wide: Let's look at the crocodile. It is green along its length and width, but it is wide only along its width. Therefore, the crocodile is greener than it is wide. From Lemma 1 and Lemma 2 we conclude that the crocodile is longer than it is wide.

For all those serious Maths buffs... lemmas and theorems!
1. Lemma: All horses are of the same colour.
Proof (by induction):
Case n=1: In a set with only one horse, it is obvious that all horses in that set are the same colour.
Case n=k: Suppose you have a set of k+1 horses. Pull one of these horses out of the set, so that you have k horses. Suppose that all of these horses are the same colour. Now put back the horse that you took out, and pull out a different one. Suppose that all of the k horses now in the set are the same colour. Then the set of k+1 horses are all the same colour. We have k true => k+1 true; therefore all horses are of the same color.
2. Theorem: All horses have an infinite number of legs.
Proof (by intimidation):
Everyone would agree that all horses have an even number of legs. It is also well-known that horses have forelegs in front and two legs in back. 4 + 2 = 6 legs, which is certainly an odd number of legs for a horse to have! Now more...

Prove that the crocodile is longer than it is wide.

Lemma 1. The crocodile is longer than it is green: Let's look at the crocodile. It is long on the top and on the bottom, but it is green only on the top. Therefore, the crocodile is longer than it is green.

Lemma 2. The crocodile is greener than it is wide: Let's look at the crocodile. It is green along its length and width, but it is wide only along its width. Therefore, the crocodile is greener than it is wide.

From Lemma 1 and Lemma 2 we conclude that the crocodile is longer than it is wide.

Prove that the crocodile is longer than it is wide.
Lemma 1. The crocodile is longer than it is green: Let's look at the crocodile. It is long on the top and on the bottom, but it is green only on the top. Therefore, the crocodile is longer than it is green.
Lemma 2. The crocodile is greener than it is wide: Let's look at the crocodile. It is green along its length and width, but it is wide only along its width. Therefore, the crocodile is greener than it is wide.
From Lemma 1 and Lemma 2 we conclude that the crocodile is longer than it is wide.