Beginner Exercise 190 / Solution

White kills marked black stones  

The stones are not invincible because of the white stone.

After , black can't save the marked stones from being retaken at .

If , then a play at the circled point catches a connect-and-die.

unkx80: Good!

For more similar examples, see the bamboo joint may be short of liberties.

How to answer ?  

unkx80: To make the discussion more complete, consider how to answer ?

Failure  

unkx80: The failure sequence shown is not a ladder at all. This can be seen after , which captures the stone and makes an atari on the stone.