Whose proof this is I think I know.

I can’t improve upon it, though;

You will not see me trying here

To offer up a better show.

His demonstration is quite clear:

For contradiction, take the mere

n primes (no more), then multiply;

Add one to that … the end is near.

In vain one seeks a prime to try

To split this number — thus, a lie!

The first assumption was a leap;

Instead, the primes will reach the sky.

This proof is lovely, sharp, and deep,

But I have promises to keep,

And tests to grade before I sleep,

And tests to grade before I sleep.

“Stopping by Euclid’s Proof of the Infinitude of Primes,” by Presbyterian College mathematician Brian D. Beasley, “with apologies to Robert Frost”.

(From Mathematics Magazine 78:2 [April 2005], 171.)