Prof. Dr. Dr. h.c. Eberhard Zeidler works at the Max Planck Institute for Mathematics in the Sciences in Leipzig (Germany). In 1996 he was one of the founding directors of this institute. He is a member of the Academy of Natural Scientists Leopoldina. In 2006 he was awarded the “Alfried Krupp Wissenschaftspreis” of the Alfried Krupp von Bohlen und Halbach-Stiftung.The author wrote the following books.(a) E. Zeidler, Nonlinear Functional Analysis and its Applications, Vols. I-IV,Springer Verlag New York, 1984-1988 (third edition 1998).(b) E. Zeidler, Applied Functional Analysis, Vol. 1:Applications to Mathematical Physics, 2nd edition, 1997, Springer Verlag, New York.(c) E. Zeidler, Applied Functional Analysis, Vol. 2:Main Principles and Their Applications,Springer-Verlag, New York, 1995.(d) E. Zeidler, Oxford Users’ Guide to Mathematics, Oxford University Press, 2004(translated from German).