February 1, 2010
Black 1 is the vital point.
If White 2, Black kills White with 3 and 5.
If White 2 at 4, Black 2 kills White.
Black 1 and 3 are crucial.
If White 4, Black creates a Ko with 5 and 7.
If White 4 at 5, Black 4 gets a Ko.
If White 2 at 3, Black lives with 2.
