Before presenting the solution proper, it is worth repeating that if Black occupies , then if
plays elsewhere or at a, then
lives. Thus Black has a sente move at
.
So the hane at kills with a bulky five dead shape. If Black tries to escape from
onwards, he will find that there is no way out. After
, if Black a, then White b blocks with a tiger's mouth.
Therefore Black tries the hane at . Sometimes it is a technique to live, but here,
is more like a trick play. Here
falls into the trap, allowing
to play the sente move described above, aiming to live with a. If
tries to kill, then
captures the
stone and connects outside.
From all the above discussion, it should be clear that the solution is for White to simply retreat from to
, not allowing Black to play a in sente. When
crawls further,
can block because this is a tiger's mouth. So Black dies as explained in the L-group page.