We have been unusually fortunate in our readers, who from four differ
ent perspectives brought our book into focus. Jean Jones, Barry Mazur,
John Stillwell, and Jim Tanton put a quantity of time and quality of
thought into their comments, which made the obscure transparent and
the crooked straight. We are very grateful.
The community of mathematicians is more generous than most. Our
thanks to all who have helped, with special thanks to Andrew Ranicki
and Paddy Patterson.
No one could ask for better people to work with than Eric Simonoff
and Cullen Stanley of Janklow & Nesbit, who make the gears that turn
writing into reading mesh with ease; nor a better, more thoughtful edi
tor than Peter Ginna, in whom all the best senses of wit unite