Xuanxuan Qijing Problem 13 / Solution
![[Diagram]](../../diagrams/15/e194f81d04d9911e1507bfd895d828dc.png)
Solution is approach ko.
The best solution for both players is to give White an approach ko, enabled by the throw-in of
.
![[Diagram]](../../diagrams/14/cdb266831abbcd242dcaa48a459b8226.png)
Black captures throw-in.
If Black captures the throw-in, then White can get another, better ko (see "Black chooses 'a' 1" & "Black chooses 'a' 2").
White exchanges
for
and then performs the key probe of
. Black's reply at a, b, and c will be demonstrated.
![[Diagram]](../../diagrams/28/9cada053b3d1f1f5b55c1582c73a6272.png)
Black chooses 'a' 1.
@ 4.
White makes a ko.
![[Diagram]](../../diagrams/23/2164289d789c24dae2730aca035f4c40.png)
Black chooses 'a' 2.
White still makes ko.
![[Diagram]](../../diagrams/31/9b64fd4fd9c9700fe0ca493dd77b158c.png)
Black chooses 'a' 3.
White lives unconditionally.
![[Diagram]](../../diagrams/3/7f68b2b4081ed6b0cea8c7c51f27be06.png)
Black chooses 'b' 1.
White lives unconditionally.
![[Diagram]](../../diagrams/10/cea5b53a320090b55055a7089d50ed3c.png)
Black chooses 'c' 1.
White lives unconditionally.