I am only 12 kyu on KGS so this is definitely a kyu-level attempt.
Dieter: (I have to write something on page 5000) This variation is to be considered too, I think. After , a play at 1 and at the marked stone are miai to live.
unkx80: Thanks for the attempts. =)
Black should play at . Then if connects, kills the group. If is played at instead, then Black plays at and White is still dead (a is a false eye).
Goantti: I'll add a missing variation.
I calculated also the variation where instead above, White plays counter-atari at . It would have worked if there had been one more line of white stones on the right. In this case White would not take at a but would atari at instead.
I'm only a KGS 14K, so this really, REALLY is a kyu attempt.
Here's my take on this problem. I think it works!
Skylancer (2K): Additional comment - if white is so kind as to connect at in response to , then black must play at immediately to kill ( in the original diagram).