RTG Problem 50 / Attempts

Failure 2  

After a and b are miai to live.

Black to move  

unkx80: This move is not easy to find... both stones will prove to be useful.

Bill: Yes, it is curiously hard to find, even though they say that to kill the first thing to try is to reduce the size of the eye space. Somehow with this problem you just want to do something clever. ;)