From Mr Graham Stalker-Wilde.

Sir, For even mentioning square roots in a public forum Gideon Rachman deserves credit ("The square root of all the European Union's problems", June 12) but it saddens me that he dismisses the Polish voting suggestion, and their wonderful slogan "the square root or death", as "obscure" and "baffling". It is complicated, but surely not beyond the numeracy of the FT readership.