On the Functional Equations Satisfied by Eisenstein Series

Editorial comments:

• This was written in 1964 and distributed for many years in a famous purple mimeographed document by the Yale University Mathematics Department. It was later published in the Springer Lecture Notes series (volume 544).
• 2015-12-02, AVP: We would like to note that we have done our best to clarify several arguments, sometimes without having fully reconstructed them. Many thanks also to Allan Adler for a long list of corrections.
• 2016-07-22, AVP: We compared several charts and text from appendix III to the author's original handwritten notes and adjusted this online text to match them.