Beginner Exercise 179 / Solution

Solution  

The objective of this problem is to introduce the technique of , which captures the stone. It also ensures the life of the White group.

Solution - main line  

If pushes in, then is the standard second line capture, which ensures an eye for White.

Solution - if black cuts  

Black attempting to cut with leaves him with a capturing race he can't win.

Failure  

Simply connecting with leaves a play open at , making miai of a and b for connection, so we can't capture the stone.