Fermat, or Perfection is Eternal

From the Fermat's Last Theorem Poetry Challenge page.

(Author: Everett Howe, Hendrik Lenstra, and David Moulton.)

"My butter, garcon, is writ large in!"
a diner was heard to be chargin'.
"I HAD to write there,"
exclaimed waiter Pierre,
"I couldn't find room in the margarine."