(;
AB[qe][qf][qh][og][oi][oj][ok][mj][lj][kj][lk][mm][mo][np][op][pp][oq]
AW[qd][rd][pe][oc][qj][nk][mk][ll][kl][kk][kn][jp][lp][mp][nq][nr][no][nn]
C[Black plays.
Source:  "Attack and Defense", Ch. 2, p. 51
         Akira Ishida & James Davies, Ishi Press]

(;
B[ml]
C[Cutting is bad!];
W[pn];
B[qo];
W[qn]
LB[po:a][nl:b]
C[White invades Black's right side.
And White A threatens B.]
)
    (;
    B[mn]
    C[Correct.  A beautiful sacrifice of three stones.]
    (;
    W[nm];
    B[nl];
    W[ml];
    B[ol];
    W[ln];
    B[on];
    W[lo]
    C[If White proceeds with capturing the three stones,
Black seals off the right side, and does so in sente!]
    )
        (;
        W[pn];
        B[on]C[If White tries to enter the right side,
Black can wedge in and cut off White.]
        )
    )
)
