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In my Don's Diary (É«ºÐÖ±²¥S, April 26) I mentioned that I was offering a prize of Pounds 100 for the first person to demonstrate a definite error in my "bare hands" proof of Fermat's last theorem. Then on May 10 Roger Fenn challenged me to a wager on the result, which, incidentally, I accepted by private letter.

Now one of Fenn's colleagues, Richard Lewin, has won the prize by showing numerically that Lemma 5.1 in my proof is wrong. It is only a second-level lemma, near the end of the work, but the mistake means that there are extra cases to be considered, which are not covered by the reasoning: so the argument as given is not complete. Roger Fenn has won his wager too, and it has cost me twice as much as I expected, but at least some unexpected clarity has been achieved. I still think the "bare hands" approach is worth pursuing, though, because Fermat, if he did it, must have done it without modern algebraic tools.

Chris Ormell

School of education and professional development University of East Anglia