(;
GM[1]
SZ[19]
AW[cd][ce][dc][fc][dq][gq][qj][dl]
AB[de][df][cf][co][fo][pp][qd][oc]
LB[dj:A][cq:C][hp:B]
C[Problem 131. Black to play.  

Before pincering the white stone on the left side, does Black need to make any preparatory moves ? Of course, Black would like to finish up on the left side in sente so he can play on the right side before White. ]
(;B[dj]
TE[2]
C[Correct Answer.  

Black must first play 1. ]
;W[fl]
C[When White jumps to 2, ... ]
;B[hp]
(;W[hq];B[ip];W[iq];B[jp];W[kq];B[ep]
C[... Black can force with the sequence to 9, ... ]
;W[eq];B[hl]
C[... then cap at 11. <= ]
)
(;W[gp]
LB[hp:3]
C[White's failure.  

In response to Black 3, White must not cut through with 4 ... ]
;B[go];W[ho]
C[... and 6. ]
;B[hq];W[hr];B[ir];W[gr];B[hn];W[io];B[gm]
C[After Black 13, White will be find herself in a severe fight. (See Problem 151 in Get Strong at Joseki 1.) ]
))
(;B[hp]
C[Failure.  

If Black plays 1 here, ... ]
;W[hq]
C[White will play 2 ... ]
;B[ip];W[iq]
C[... to 4, ... ]
;B[jp];W[di]
C[... then extend to 6. <= ]
)
)