Dropped after reading the first 3 chapters. The book has an interesting organization and goes beyond the standard exposition, but it has awful explanations: the author doesn't make proper definitions nor proofs (although I think he believes he does). His development of the subjects looks more like a brief summary of concepts for people who already know them than like a proper introduction, with the already mentioned problem of bad exposition (I know these subjects, but I don't think I could have correctly learnt them from this). Add plenty of whimsical, preposterous and arrogant claims in footnotes (which show the author is not strong on epistemology either, clearly related to the fact that he doesn't care about proper definitions), and typos in many mathematical developments. Better to avoid this book and read another one on the same subject.