erislover: It seems that white can get a few different kos, all direct, but black gets the first capture. Still, it seems like a great ko for w who is risking (apparently) nothing. I don't see how to kill unconditionally or to have white get the first capture.
If black captures at a instead of , then white at b kills unconditionally.
idigo: at b kills unconditionally. Black suffers from shortage of liberties, and won't be able to take for himself.
erislover: Ah, nice, I missed the ol' SOL tesuji.