British Go Journal No. 56. June 1982. Page 25.
Solution 1 |
White 1 is the centre of symmetry. After 4, White throws in at 3 and Black can't connect.
Solution 2 |
Solution 3a ||
Solution 3b |
White must lob in a stone at 1 in Dia 3a, if he first plays 1 in Dia 3b Black can live since 3 and 4 are miai.