Under the Stones Example 2
I love this tesuji so much, that I can't resist the temptation to talk about some variations on the same idea. The only difference is the shape of the four sacrificed stones, which isn't square.
would be a terrible blunder of course, since it would almost force White to live with .
is the real suji here. White has no choice but to capture the four black stones with to get a chance to make a second eye. But ...
... annihilates White's hope and the whole white group dies.