(;
AB[pc][pd][me][oe][nf][qj][rj][lk][ll][ok][ol][pk][ql][mm][mn][mo][mp][mq][rm][in][jn][kn][jo][jp][ko][no][oo][po][qo][ep][hp][np][fq][kq][kr][ks][lq][pq][qq][cr][dr][qr]
AW[nc][dd][kd][md][od][ne][pj][qk][rk][kl][km][ml][nl][pl][pm][pn][rl][lm][ln][lo][lp][nm][nn][cn][qn][rn][io][ip][ro][rp][dp][gp][kp][op][oq][cq][jq][jr][nq][nr][gr][mr][pr][ls][os]
PL[W]
C[White's response to Black's marked wedge?

Source:
    "Tesuji in an Actual Game" (originally from Weichi World)
    Duan Rong 7P
    American Go Journal, Vol. 36, No. 2, p. 39]
TR[hp]
(;
W[ho]
C[White cannot capture by pushing out here.];
B[hn]
C[First Black has this sente push.];
W[go]
C[Can you read out the following common and straightforward capture sequence for Black? ];
B[jk];W[kk];B[kj];W[lj];B[mk];W[jj];B[ki];W[jl];B[ik];W[il];B[hl];W[hk];B[ij];W[hm];B[gl]
C[White's center collapses.]
)
    (;
    W[iq]
    C[Instead, in the actual game White mistakenly connects here -- the losing move.

Reading out Black's winning sequence now is more complicated than the previous variation, but the reader should be able to identify the general plan.];
    B[ho];W[gq];B[hq];W[hr];B[hn]
    C[As in the previous variation, this move threatens White's 7 stone center group.];
    W[il];B[fo];W[eq];B[ir];W[is];B[js]
    C[White loses the 5 stones.];
    W[ir]
    C[For example ...];
    B[fp]
    )
    (;
    W[gq]
    C[White should have connected here.];
    B[ho];W[ir]
    C[Good move.]
    (;
    B[iq];W[kk]
    C[Now White can strengthen the center stones.];
    B[fo];W[hr];B[fr];W[qp]
    C[White wins the semeai.];
    B[pp];W[rq];B[rr];W[sr];B[gs];W[qs];B[rs];W[ps];B[hs];W[on];B[fp];W[lr]
    )
        (;
        B[kk]
        C[Turning here doesn't work for Black either.];
        W[im];B[hm];W[il];B[hk];W[ik];B[ij];W[hl];B[gl];W[jm];B[iq];W[hj];B[gk];W[jj];B[ii];W[jk]
        )
    )
)

