by Peter T Johnstone, Oxford University Press. Volume 1 ISBN 0198534256 £100.00 (€158); volume 2 ISBN 0198515987 £100.00 (€158); both volumes ISBN 01982496X £175.00 (€277).
This comprehensive two volume set on the theory of topos – the abstract construction of algebraic geometry – owes its title to the Indian tale of four blind men asked to describe an elephant. Each of them inspects a different part of the animal by touch, and each comes up with a very different description. The same, says Johnstone, is true of topos – how you describe them depends on how you approach them.