Killing Sequence 1 (The Easy One)
Looks are very deceptive... It looks as if Black is alive. However, the hane at , and , kill unconditionally.
Notice that Black can't play at at .
Killing Sequence 2 (The Harder One)
The placement at works, too. The aji caused by becomes apparent and Black is now unconditionally dead.
If Black connects at , White can play the hane at to kill. After and , Black can't play at a because of shortage of liberties. So if he captures the two stones, White kills him at a.
Playing in the previous diagram at here is wrong. Black descends at , and then makes a seki with .
tries to expand the eye space, but with the ataris at and ...
...White continues his atari sequence, and occupies the vital point of . Black dies with a bulky five shape.
Black connects at , and White responds with . Then and are also miai.
Maybe this variation is not needed? In response to , White cuts at and plays atari at , capturing the stones.
We shall now consider Black's other answers to the hane (the marked stone). is a possible move, but reduces Black to a bulky five. If Black plays , White plays at ; and a and b are miai.
Well, must never be played at a, or else Black plays atari on three stones at c, White d, and makes two eyes.
This way of resistance is also useless. Perhaps the other variations are unnecessary?