It is the first book in the history of chess literature (and probably in all literature ever) to be effusively praised by five world champions in the preface, afterword and endorsements, from Garry Kasparov to Magnus Carlsen. Half of it consists of the deep relationships between mathematics and chess.
Garri Kasparov writes in the preface: "For decades Christian Hesse has been thinking about the relations between chess and mathematics. The chess logicals he invented add a whole new dimension to chess studies and mathematical logic. Frederic and Christian are a dream team who have succeeded in writing a chess book like no other."
Reigning world champion Magnus Carlsen adds in the afterword: "Christian shows himself to be a creator of brilliantly composed chess puzzles, which he presents in his newly created art form as Zen Logicals."
The book is being published these days by Droemer.