Fermat: Margin Capacity Exceeded

Pierre de Fermat claimed that no nonzero integers satisfy xⁿ + yⁿ = zⁿ for integer n greater than two, then wrote that he had a marvelous proof which the margin was too small to contain. The claim resisted proof for more than three centuries.

Instead of inventing mysterious notation, the shirt shows the actual theorem, its conditions, and a deliberately unavailable proof: the margin has reached capacity.