Apart from a number of minor corrections and changes, a substantial reformulation and up-dating of Chapters 14 and 15 has taken
place. This reformulation and up-dating is a major and very welcome
contribution from my friend and colleague, Dr J.W. Sanders, to whom I
express my sincere thanks. His efforts have produced a much better
result than I could have achieved on my own. Warm thanks are also due
to Dr J 0 Ward, who checked some of the revised material.
New Sections 16.9 and 16.10 have also been added.
The bibliography has been expanded and brought up to date, though it
is still not exhaustive.
In spite of these changes, the third paragraph in the Preface to the"
revised edition of Volume 1 is applicable here. What has been
accomplished here is not a complete account of developments over the
past 15 years; such an account would require many volumes. Even so, it
may assist some readers who wish to appraise some of these
developments. More ambitious readers should consult Mathematical
Reviews from around Volume 50 onwards.