This shape is elswhere on SL but I can't find it. Dieter
Black can set up a useful sequence: strike at the waist of the keima.
Charles A comment: should White play atari?
This is a typical 'good style' question. Here the answer seems fairly clear.
If this happens, White at a is less powerful (because assists Black at b).
Not entirely clear, though.
If the fighting in intense, White might prefer this. In principle is bad style (rather than taking
off immediately). Sometimes White might want to form one immediate eye; and leave the cutting point at c. In that case it could be true that the aji of White at d later is worth having; and more important than the direction of the bend at a.
If is actually going to be played, therefore, it looks as if playing
atari first will sometimes be correct.