(;
AB[br][cr][dq][eq][gr]
AW[cq][dp][cp][ep][fp][lo][lq]
PL[W]
C[White plays.

Source:
    "Tesuji", James Davies]
(;
W[gq]
C[Slack.];
B[fr]
C[Black repairs the defect.];
W[hr]
LB[hq:A][ir:B]
C[White can block here in gote, but now has to worry about weaknesses at A and B.]
)
    (;
    W[fr]
    C[Tesuji!]
    (;
    B[fq]
    C[Black can easily cut off the stone, but ...];
    W[gq];B[er]
    C[... Black has to come back to defend.];
    W[hr]
    C[Now White can block in sente.];
    B[fs];W[hq]
    C[White has great outside thickness.]
    )
        (;
        B[er];W[gq];B[hr]
        C[And if Black tries to avoid transposing to the previous correct variation, ...];
        W[es]
        C[... Black's shortage of liberties prevents a connection.];
        B[ds];W[fs]
        C[... ]
        )
    )
)

