Tsumego From Games 35 / Solution

The purpose of  

The purpose of is to capture a stone in sente, that is, it also aims at capturing a bunch of White stones with , resulting in a connect and die.

Thick  

is a thick play, eliminating Black's threat to run out to the center. Later is answered with .

Thick  

Later, if , - .

Comparison  

In the SGF comments, it was claimed that Black cannot escape. Whether can escape or not is not immediately obvious, and even it can be captured now, it leaves serious aji behind later.

Moves 66 to 73  

The game proceeds as shown. If has been played at , then Black can atari at and hane at , but White can hane at a. (In this diagram, should be at , should tenuki (and consider the chance to play at b) or play at a.)