(Referenced by 363; 387; 538)

: ( 504)
This move reduces White's potential ko-threats on the left side, but will not lead to success either, due to a double-ko (found by Joachim Meinhardt). The situation is very confusing, thus we show several variations of our solution here, in detail.

: (A 534)
In 2010 [LIT. 5; page 380 ff.], Cheng shows several variations for , ...

(Referenced by 137)

: (A 535)
... and especially after at . Cheng evaluates the outcome of this sub-variation as good for Black, but we believe that this may not be correct.

:
Now, Black can choose between connecting some of his stones on the first line, with , and on the second line, with .

: (94 541)
We examine the connection on the edge first.

: (99 543)
If Black takes the lower White stone, a double-ko results, which Black cannot win.

:
Eventually Black has to capture White's stone in the corner.

:
Thereafter, White gets two eyes, with and , so winning the game.