Interesting, but woefully incomplete since it doesn't include a single turnstile-based statement. I'm still looking for the cheat sheet that includes an explanation for how to read and comprehend anything written by Simon Peyton-Jones.
1: I call it "introductory" because many of the relevant proofs are left as an exercise to the reader. But truthfully, people I've spoken to with a direct influence on the book have mentioned many a time that harper excludes them because he expects you to know them or be able to figure them...
I got that very early on. The dedication to craft cheating devices (even in primary schools) and cram information as densely as possible meant you had to read it a lot, categorize, prune and simplify it to the point you basically knew it backwards.
It failed in high school when I got a graphing calc capable of storing "large" corpus of text. You didn't have to think a lot (mostly careful typing) and it grew too large to even remember everything you typed in.
Do PhD students have written exams? I thought they did research and wrote papers? How can you write an exam to test a PhD student when they are the ones coming up with the knowledge in the area?
PhD students take classes, and some of them do have written exam (in CS theory more than other parts of CS). In the US, where the PhD is 5 years, you spent a good portion of the first 2 years taking classes.
Before coming up with new knowledge you need to know what's already out there.
10x10 magic square, I guess (tested that by summing a few rows and columns modulo 10; got 5 everywhere. Rows and columns should add up to 4950/10, so that doesn't disprove the hunch)