(;
AB[id][jc][kc][lc][mb][md][nd][od][pd][qc][pb]
AW[gc][kb][lb][ma][mc][nc][oc]
C[Black plays.]
(;
B[na]
TR[mb]
C[Black aims to create a false eye at the marked point, but ...];
W[oa]
C[... White cuts off both stones.];
B[la];W[nb];B[ma];W[ka];B[ma];W[ib]
C[White can connect out.];
B[jb]
C[For example ...];
W[ja];B[hb];W[hc];B[ic];W[ia]
C[And White has enough internal liberties to save all the stones.]
)
    (;
    B[jb]
    C[Seemingly best, but ...];
    W[ka];B[na];W[oa];B[la]
    C[... Black only has a ko.]
    )
    (;
    B[ka]
    C[This "clearly useless" move is the only move that works!];
    W[jb];B[ib];W[ja];B[na]
    (;
    W[oa];B[la]
    C[Now when Black captures here with atari, White doesn't have time to squeeze for 2 eyes.];
    W[ma];B[la];W[nb];B[ma]
    C[White has only one eye!]
    )
        (;
        W[nb]
        C[Capturing immediately is no better.];
        B[oa]
        C[White still has only one eye.]
        )
    )
)

