(No. 208: Apr. 17, 2000)
Elementary level: Answer
Black 1 is the vital point.
If White 2, Black lives with 3.
Elementary level: Wrong Answer
Black 1 lets White play on the vital point 2.
Intermediate level: Answer
Black 1 and 3 are both the vital points. White dies.
Intermediate level: Wrong Answer
Black 3 allows White to live with 4 to 8.