So I'm taking undergrad set theory with the mad genius type. He's a somewhat famous math logic guy, and he's been doing it for so long, and so much, his notation is sloppy (i.e., it makes sense to him and no one else).

I feel like with this of all subjects, spot-on, precise, unambiguous notation is key. Anything less than that will make this intense subject become impossible.

My question is, what do you guys do when you have a professor like this? (sloppy/ abbreviated notation, overly-terse proofs, etc.). Also, any advice for set theory?