: ( 648qe)
Black connects the ko in the left centre.

Ko:

:
White captures in the upper left corner.

:
White's previous move is absolute sente, so Black has to connect at the left edge.

:
White connects her single stone in the upper right.

:
Black recaptures the ko.

:
White continues with the Main Semeai.

:
Black connects.

Black plays 1/1 reduction.

Capture Variation:

Compared to the superordinate variation ...

• White destroyed one point of Black's territory in the upper left corner.
• Black's cumulatead gain in the left centre is two points.
• Black's cumulatead gain in the lower left corner is one point.
• Black did not capture White's stone in the right centre, so losing three points.

In total, Black lost one point.

White + 2 => White + 3

Semeai Variation:

Compared to the superordinate variation ...

• White destroyed one point of Black's territory in the upper left corner.
• Black's cumulatead gain in the left centre is two points.
• Black's cumulatead gain in the lower left corner is one point.
• White captured one Black stone less in the upper right, so losing two points.
• White got an additional point of territory in the upper right corner.

In total, Black gained three points.

White + 2 => Black + 1