impu1se: I think this is right. White must play to keep black from making an eye. Black will now live due to the double ko. However, white has a nice source of ko threats.
IlyaM: Yep, this is correct solution. Playing before
also works. Fortunaly in my game where this position appeared it appeared very late in the game so there was no ko-fights.
if white play at , black
live.
can also play at c, but no difference made.
Bill: Through the result is seki.