Problem 1 -- Prove that a crocodile is longer than it is wide.

We first prove the following:

Lemma -- "A crocodile is longer than it is green"

To see this, just examine the crocodile: It's long on the top and on the bottom, but it's only green on the top. Thus, it is longer than it is green, proving the lemma.

Now note that the crocodile is green along both its length and its width, but it is only wide along its width. Therefore, it is greener than it is wide. This, along with the lemma, completes the proof that a crocodile is longer than it is wide.