: ( 648br)
White continues with the Main Semeai.

:
Giving atari in the centre now is too unreasonable, violating the current restriction.

The same principle would apply, had Black given atari with at the upper edge, instead.

:
White simply ignores Black's previous move and continues with the Main Semeai.

Capture Variation:
At White's decision point, Black's large group in the upper right will have only six liberties left (), which is one liberty too few to survive the Punishment Semeai.

White will win the game by a large margin.