I checked out this book from my library, and read it again (the last time being several years ago).
I highly recommend it!
Although, and maybe I missed or overlooked it if it was talked about in the book as some puzzle, but it seems that there is an error on the cover of the book. (absence of a + or - sign)
I highly recommend it!
Although, and maybe I missed or overlooked it if it was talked about in the book as some puzzle, but it seems that there is an error on the cover of the book. (absence of a + or - sign)