•Complexity: examples in class are simple; but in general the proofs get quite complex
•Informal arguments: We are all gamblers:
– “If you play like this […] you will always
win”. We usually accept such statements after thinking about
[…]
–“here is a property
not expressible in FO !”. We don’t accept that until we see a formal proof.
•Logics v.s. games: Each logic corresponds to a certain kind of game.