Gokyo Shumyo, Section 1, Derived Problem 56

Var 2  

Black has enough oustide liberties to capture the four stones.

Var 3  

Black makes miai of a and b.

Var 4  

(unkx80: Why not play 2 at 5? :-))

Var 4 - ctd  

The points 1 and 2 are miai