: ( 169)
We think that Black can continue by further reducing White's corner territory with here. White's only hope (of making profit from not blocking at with = ) is to fight a ko, because connecting Black's atari with at will give White the same amount of territory as with our solution. White may choose between , , and , now.
: (B 173; C 174)
If White connects on top with , Black simply plays the guzumi exchange of , , and then starts the Crosscut Sequence in the left centre with . His top right group has 13 liberties (, ) in the marked area, which makes sure that White will not win the Punishment Semeai. White did not gain territorially in the corner.
Because Black can win unconditionally, there is no need to start a ko, with cutting at with .