Xuanxuan Qijing Problem 226 / Solution
If , this is reduced to Xuanxuan Qijing Important Shape 1.
'x' and 'y' are miai, white can make the exchange by playing one of them anytime, but it doesn't change the rest of the solution.
secures an eye but kills.
has miai of 'x' and 'y' to escape.
can't get both 'x' and 'y'
at 'a' is the same.
at any other move doesn't even reduce white's eye space.