(;AB[bd]AB[cd]AB[ce]AB[de]AB[df]AB[dg]AB[dh]AB[ch]AB[ei]AB[fi]AB[dj]AB[cj]AB[bj]AB[bk]AB[bl]AB[am]AB[ai]AB[ag]AW[be]AW[bf]AW[cf]AW[cg]AW[bg]AW[bh]AW[bi]AW[ci]AW[di]AW[ak]AW[ej]AW[ek]AW[dk]AW[ck]AW[cl]AW[bm]AW[bn]TR[ak]C[If white plays a9 hoping to avoid a ko, how does black respond?]AP[goproblems]
(;B[ae];W[aj]
(;B[al];W[aj]
(;B[af]C[Yes!RIGHT])
(;B[ak];W[an])
(;B[ah];W[af]))
(;B[ah];W[al]C[Oh no!])
(;B[af];W[al]C[Oh no!]))
(;B[aj];W[ah])
(;B[al];W[an])
(;B[ah];W[aj];B[al];W[aj]
(;B[ak];W[an])
(;B[ae];W[af]))
(;B[af];W[ae];B[ad];W[ah]))