This is one of those books that is so deep that I doubt anyone can read it cover to cover without having to go back and puzzle over the contents of some of the chapters. It is intended as a commentary on Turing's paper which, in some ways, due to the notation Turing uses, is more difficult to understand than it needs to be. Petzold plows through this giving several lines of commentary and examples to each line of Turing's paper.

Petzold demonstrates his knowledge of computing and mathematics and has obviously read and understood the mathematical papers that form the backdrop and purpose of Turing's paper and he refers to them knowledgeably.

No book on Turing can avoid the tragic story of his short life and Petzold covers this in a sensitive way intertwining both the depth of the mathematical theory and historical background in a seamless way.

I'm reminded of Bill Gates review of Knuth's work: "If you think you're a really good programmer . . . read (Knuth's) Art of Computer Programming . . . You should definitely send me a résumé if you can read the whole thing.". This book is, along with Godel, Escher, Bach in the same category.

This book is of the level of advance Computer Science Degree and should define Petzold's legacy more than all of the seminal Windows programming books that he has written over the last 20 years.