(;
AB[rq][qq][pp][po][np][no][nr]
AW[pq][qp][rp][qo][qn][pn]
C[White plays

Source
    Tesuji, Ch. 5, p. 87,
    James Davies, Ishii Press];
W[pr]
C[White's 1st move is obvious.

But worth remembering are White's
follow ups to Black's defensive
resources.]
(;
B[qr];
W[rs]C[White takes the key point,
and Black loses the semeai.]
)
    (;
    B[rs];
    W[sr]C[Again, White takes the key point.];
    B[rr];
    W[qs]
    )
    (;
    B[rr];
    W[qs]C[And Black cannot avoid transposing into the previous variation.]
    )
)

