TJHProblem 7/ Solution

White kills  

hotcoffee: If doesn't connect, white can capture 2 stones and black has dead shape (below). If at 'a', at and black is short of liberties.

Variation  

If Black doesn't defend against the atari, then White will capture two stones with . By symmetry there are only 3 variations based on where is placed (excluding a sensible tenuki). As Black can only make a bent-3 or 2x2 square eyespace, he is dead. eg. in this position 'b' and 'c' are miai for the kill.

Black lives with 1  

There are several variations of white attacks, in most cases white has 3 ko-threats, before the aji is gone and black is untouchable.

Black lives  

is also appropriate if is played at 'a' or 'b'.