All you need to know about Carpenter's Square - 31
Submitted by macelee on 2013-02-21 13:38; Last upda
ted on: 2018-11-17 17:35
Diagram 31.1: White to play
This shape is very similar to Shape 30.
Diagram 31.2: Solution
The solution is similar too. 
is still the key point and black corner suffers the same fate as in Shape 30.
Diagram 31.3: Variation
does not work either. White has longer liberty. Note that white cannot play 
though.
Diagram 31.4: White fails
is incorrect. is important to form a ko. If black connects at first, allowing white to occupy , the corner would be dead.
To summarise: this is another simple problem. The tesuji in Diagram 31.2 should be memorised.
