Nice work on finishing your book. My question to you is how have you approached teaching Lambdas. This is something I have been vaguely aware of since my university days, but it has not quite 'clicked' yet, if you know what I mean.
Off topic, who do you fancy for the World Cup. I think Argentina will probably do it, based on track record of European countries in south America, but it could be one of the more open tournaments for a long time with a number of teams all in with a shout.