Scartol: is the move for Black, threatening the snapback throw-in at a. White can't threaten the double-capture at b, because Black will immediately take and have the extra room to make the snapback happen. Black emerges with a victorious grin.
Fhayashi: is futile, right? Isn't it better played elsewhere?
kishi Can white recover this corner in any way? Or save itself?
unkx80: The short answer is, no.
abcd_z: The solution I can up with had a slightly larger snapback, but it amounted to the same thing. White is dead, and an attempt at a would lead to a snapback at b.
HolIgor: Answer to the last diagram
The variation at the last diagram does not work. White captures and wins the semeai by the virtue of an eye against no eye. If Black a then white captures with b, if Black b then white plays c and yet black is short of liberties. White has all the time in the world to capture.