: ( 532)
If White throws in at , which is too early, and therefore not correct ...

: (A 536)
... it is not correct to capture this stone with .

:
Black must connect at , instead.

:
After the hane of , White throws in a second time at , to spoil Black's shape.

:
Black must protect his weakness of , so White gets the atari of .

Black suffers from a shortage of liberties; if Black connects at , White will capture at , and vice versa.