is a mistake, giving a chance to turn the already alive corner into a ko. If at a, white will play at , and black will be totally dead.
demetria: With the above solutions, black looks to have only false eyes. Is there any way to make this a true living shape?
If white takes the next vital point, A, it leaves black with one eye (or 2 small eyes at best, which is better than nothing). If black takes the vital point the eyes are still false. White can follow up with B as well.
Here, white can force black to ruin his own eye. White can at this point threaten a capture if she can manage to seal black off the rest of the way and win a ko at A.
The point here is : How does black prevent all this from happening?
unkx80: My answer to your queries is in the two diagrams below.
Tas: A bit of explanation: The eye at a is not false since is captured. If white b, black to keep the eye real.
Nico3ck?: How about Black at ? I can't see white killing it.
Herman After , black's eye is false
Anonymous: Black captures and white plays a throw-in with to make it a false eye.