EVENT
BOARDSIZE 19
SETUP W Q17 O17 N17 R14 Q15 B16 C14 C11 
SETUP B C17 D16 F16 K17 O16 R16 
MARK 1@Q15
COM
Problem 70. Black to play.  

If White defends with 1, Black has a brilliant tesuji to destroy
White's corner. Where is it ? 
ENDCOM
B 1 Q18
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

Black 1 is a spectacular move.
ENDCOM
W 2 R17
COM
If White plays 2, ...
ENDCOM
  VAR
  W 2 P17
  COM
  Variation.

  If White connects with 2, ...
  ENDCOM
  B 3 R17
  COM
  ... Black can live with 3. White's corner territory is completely
  destroyed.
  <=
  ENDCOM
  ENDVAR
B 3 P16
MARK A@Q16 B@P17
COM
... Black 3 threatens to link up with A or B.
<=
ENDCOM