Gokyo Shumyo, Section 1, Problem 62 / Solution
is the traditional solution. at also lives. at a descent is a better way to live.
If immediately, it is quite clear that makes miai of a and b, making an eye at the circled point (as in the solution).
The points and are miai (see variation). makes miai of a (atari) and b (destroys second eye).
Now there is no chance of a becoming an eye.