EVENT
BOARDSIZE 19
SETUP W C12 C13 D13 E14 E15 C16 C5 P16 J15 H16 H14 H13 J12 K14 L14 L13 M13 N13 N14 
SETUP B C18 E17 F16 F15 F14 E13 D12 D11 C11 Q4 R16 N17 N15 M15 L15 K15 M16 M14 K17 J13 J14 
MARK \t@J12
COM
Problem 129. Black to play.  

White has just secured the center with the marked stone (White
16 in the Correct Answer of Problem 85). What should Black do
next ? 
ENDCOM
B 1 B16
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

Attaching with Black 1 is a severe attack on the white stones.
ENDCOM
W 2 B15
  VAR
  W 2 B17
  COM
  Variation.

  White can't resist with 2.
  ENDCOM
  B 3 B15
  W 4 C17
  B 5 C15
  W 6 D15
  B 7 B18
  W 8 A16
  B 9 D16
  COM
  The sequence to Black 9 will follow and the white stones are
  dead.
  <=
  ENDCOM
  ENDVAR
B 3 B17
W 4 C14
B 5 D16
W 6 D15
B 7 B12
W 8 B13
B 9 B11
W 10 A14
COM
White can live with the sequence to 10, but she ends in gote,
while Black expands his corner territory and increases his influence
facing down on the left side.
<=
ENDCOM