Mark Seemann's Reviews > The Annotated Turing: A Guided Tour Through Alan Turing's Historic Paper on Computability and the Turing Machine

The Annotated Turing: A Guided Tour Through Alan Turing's Historic Paper on Computability and the Turing Machine by

This book reprints Alan Turing's 1936 scientific paper On Computable Numbers, with an Application to the Entscheidungsproblem, with 'a bit' of commentary.

The paper is 36 pages, so the remaining 300+ pages are Charles Petzold's explanation of the paper. The book starts with explaining the (mathematical) context of the paper: what had come before, which problem it addressed, and some important mathematical tools and results required to understand the paper.

The paper itself is terse and dense, so even armed with Petzold's explanation of the context, I'd been unable to follow it had he just dumped it verbatim. What he does, instead, is that he cuts it into small fragments, and then he takes the pages required to explain what happens in Turing's text. He does a tremendous job of that. Every time I felt that I didn't understand a particular definition or formula, Petzold's notes comes to the rescue.

Armed with my 20+ year old, passive maths knowledge, I was able to follow most of Turing's paper. It probably helps that I'm a professional programmer, so I found the description of computing machines tractable, although I had to pay close attention and work through some of the pages more than once.

This is possibly the most spellbinding hard-to-read book I've ever read. The book is hard to read in the sense that it required all my attention to follow, but it was just at the right level for me, and I enjoyed it throughout.