This page contains a discussion on problem 15 in Yang Yilun's Ingenious life and death puzzles, Volume 1. I thought it contained an error, but Leon Matoh? gently pointed out my mistake.
On page 31, solution diagram 15 mentions:
"If at
,
at
is sente. Next, White can play
to live."
If ,
...
is a mistake :
makes miai of a and b to kill.
If White plays atari at ,
reverts to the original solution diagram.
This sequence makes miai of a and b.
Leon Matoh 5d points out:
If Black prevents White from making a second eye at , then
makes miai of a and b, capturing some stones and living.