1
Mary Lane deserves our special thanks for her part in bringing this
volume to a successful completion.
The referee deserves thanks for careful reading and many useful comments.
2
The author thanks H. Miller for a careful reading of an earlier draft.
We thank the referee for recommending various improvements in exposition.
It is a pleasure to thank R. Greenberg for bringing his criterion for...... to our attention, and for generously sharing his ideas about it.