Couldn't help laughing at the image of Homer Simpson in your Science + Health section of Feb. 2 ("Examining the secret square root of D'oh!"). However, mathematical integrity behooves me to point out that what is printed along with the image (reproduced above as published) is not Fermat's Last Theorem: What is written is "x times n + y times n = z times n," whereas the theorem (proven to be true in 1993) states that for n at least 3, there are no positive integers x, y and z such that "x to the nth power + y to the nth power equals z to the nth power." In other words, your multiplication should be exponentiation. Poor Homer.

On the other hand, that doughnut he's eating looks pretty good. It perhaps started out as a cup of coffee, since the latter can be smoothly deformed into the former to create a Homeresque "breakfast of champions."

Jeff Rosoff, St. Peter, Minn.

The writer is a professor of mathematics at Gustavus Adolphus College.