EVENT
BOARDSIZE 19
SETUP W K16 M17 O16 
SETUP B D16 H17 M16 Q16 Q14 
MARK 1@M17
COM
Problem 6. Black to play.  

White attaches underneath with 1. How should  Black answer ?
ENDCOM
B 1 L17
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

Black should hane at 1.
ENDCOM
W 2 L16
B 3 N17
W 4 M18
  VAR
  W 4 M15
  MARK 3@N17
  COM
  Variation.

  If White answers 3 with 4, ...
  ENDCOM
  B 5 M18
  COM
  ... Black captures with 5.
  ENDCOM
  W 6 N16
  B 7 M17
  MARK B@N15 A@L15
  COM
  After connecting at 7, Black will aim at A or B.
  <=
  ENDCOM
  ENDVAR
B 5 N16
W 6 N18
B 7 O17
MARK A@K17
COM
A sharp exchange takes place up to 7. Black now threatens A.
<=
ENDCOM