EVENT
BOARDSIZE 19
SETUP W C16 E16 H17 C12 R17 P17 O18 R14 Q14 R11 
SETUP B K17 C10 O17 O16 P16 Q16 R15 S15 
MARK 2@O17 1@O18
COM
Problem 131. White to play.  

Against White 1, Black 2 is a strong move. How does White live
? 
ENDCOM
W 1 P18
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

Connecting at 1 is the proper move.
ENDCOM
  VAR
  W 1 Q17
  COM
  Failure.

  Connecting at 1 is bad.
  ENDCOM
  B 2 N18
  W 3 P18
  COM
  After White 3, ...
  ENDCOM
    VAR
    W 3 S18
    COM
    If White 3 here, she lives, but ...
    ENDCOM
    B 4 P18
    COM
    ... Black can capture a stone in sente with 4.
    <=
    ENDCOM
    ENDVAR
  B 4 T18
  COM
  ... Black kills her with 4.
  <=
  ENDCOM
  ENDVAR
B 2 N18
COM
After Black blocks with 2, ...
ENDCOM
W 3 S18
COM
White lives with 3.
<=
ENDCOM