(;
GM[1]
SZ[19]
AW[dc][ce][gc][kd][mc][qg][qj][pk][qm][dp]
AB[id][oc][qe][pd][og][oj][nl][ql][oq][qp]
TR[qm]
C[Problem 39. Black to play.  

White attaches with the marked stone in order to rescue her stones under siege. How should Black respond ? ]
(;B[pl]
TE[2]
C[Correct Answer.  

Black should push up with 1 and separate the white stones. ]
(;W[ok]
C[If White 2, ... ]
;B[ol]
C[... Black could play 3 and secure the territory on the lower right side. <= ]
)
(;W[rl]
C[Variation.  

But White could hane with 2, ... ]
;B[rk]
C[... Black will block with 3 and, ... ]
;W[qk]
C[... if White cuts with 4, ... ]
;B[rj]
C[... Black will crawl to 5. This is quite a severe move. ]
(;W[ri]
C[If White 6 here, ... ]
;B[rm]
C[... Black will capture a stone by playing at 7. <= ]
)
(;W[rm]
C[If White connects at 6, ... ]
;B[qi]
C[... Black plays 7. Either way, White's position has collapsed. <= ]
)))
(;B[rm]
C[Failure.  

If Black hanes at 1, ... ]
;W[pl];B[qn];W[pm];B[rk];W[pn];B[po];W[nn]
C[... White will escape into the center with the sequence to 8. <= ]
)
)