: ( 648dv)
White connects her single stone at the upper edge.

Ko: ; ; ;

:
Black must continue with the ko fight.

: (A 648dx)
White simplifies the matter by blocking immediately.

Alternatively, she might consider inserting her kikashi in the lower left corner. This move will not affect the final scores, and so lengthen the ko fight unnecessarily.

:
Black is able to terminate the ko fight. He defends his lower left corner.

:
White has to connect the ko - sooner or later.

:
The Main Semeai continues.

Black plays 2/3 reductions.

Capture Variation:

Compared to the superordinate variation ...

• White's cumulated gain at the upper edge is two points.
• Black destroyed one point of White's territory at the top.
• Black's cumulated gain in the lower left corner is two points.
• Black did not destroy one point of White's territory in the upper right corner.

In total, gains and losses compensate for each other.

White + 1 => White + 1

Semeai Variation:

Compared to the superordinate variation ...

• White's cumulated gain at the upper edge is two points.
• Black destroyed one point of White's territory at the top.
• Black's cumulated gain in the lower left corner is two points.
• White captured one Black stone less in the upper right corner, so losing one point.
• Black captured one White stone less in the lower left corner, so losing two points.

In total, gains and losses compensate for each other.

White + 1 => White + 1