From page vi:
The structure of the book is a bit like stone fruit, with a soft wrapping of a hard core, …
Transfer entropy is hard to calculate from real data.
I love that they provide a “List of Key Ideas”, a “List of Open Research Questions”, and a “List of Key Results” in the opening along with the traditional sections of symbols used, acronyms, list of tables, etc. More texts of all stripes should be doing this!