A Hilbert space problem book

the long version

The purpose of this book is to use problems and their solutions to communicate to the reader many of the central techniques and ideas of Hilbert spaces. The first part consists of problems, frequently preceded by definitions and motivation, and sometimes followed by corollaries and historical remarks. Most of the problems are statements to be proved, but some are questions, and some are challenges. The second part, a very short one, consists of hints. The third part consists of solutions: proofs, answers, or constructions, depending on the nature of the problem. The solution may also introduce standard nomenclature, discuss the history of the subject, and mention pertinent references.--