S4M

Looks neat! My only criticism would be that the solutions are given right after the questions so I couldn't help to read the answer of one question before thinking it through by myself.

I will join if someone organizes it!

It said that the quantity sum(1/(n log n) for n in A) is always finite when A is a primitive set. The "operation done to each element of the set" is n -> 1 / (n log n).

You are lucky, I kept having the same message asking me to prove that I wasn't a robot and couldn't access to the article at all (same reason as you, they "detected unusual activity from your computer network").

That's just a more sophisticated version of sleep sort.

Hi, I would be interested to help a bit, as I think human trafficking is disgusting and should be stopped. Do you have a contact detail - my personal email is in my HN profile)?

I played three games and lost them all. It's as you said, I felt that in the opening they knew something I didn't and they entered quickly in my camp. The strange thing is that when I played last year, I didn't have that feeling at all, the games felt pretty even - I won one game because my opponent resigned after I declined his draw offer.

If you want we can play some games some day. My email is in my profile if you're interested.

I just went on playok to play couple of games of xiang qi and... I also got murdered...

I don't have the source, but I remember read the lichess didn't want to implement other board games in their interface.

For XiangQi, I know that you can play it on playok.com (I know the rules and played a few games last time just to get the feeling, but I am more into chess and shogi...).

Hyperion and Endymion by Dan Simmons are quite good.

It's set in the far future, when humans have colonized the whole Galaxy, and AIs have become so advanced that they are sentient and have their own world, somewhat parallel to the human world.