(;AW[dc]AW[fd]AW[fe]AW[ff]AB[cc]AW[cb]AB[bb]AB[db]AW[eb]AW[gb]AB[dd]AB[ed]AB[ee]AB[ce]AW[ec]AW[cf]AW[df]AW[ef]AW[ch]C[Can you kill black? As unconditionally as possible?]AP[goproblems]
(;W[bd];B[bc]
(;W[cd];B[ca]C[Nice tesuji, but you let black live.])
(;W[da]C[Right, black is dead now. For example with the A - B - C - D - E - F variation.RIGHT]LB[be:a]LB[ae:b]LB[af:c]LB[ad:d]LB[ac:e]LB[ba:f]))
(;W[be];B[bd];W[de])
(;W[da];B[bd]
(;W[de];B[ac])
(;W[ba];B[bf]
(;W[de];B[ab]C[Alive.])
(;W[ab];B[ac]C[Only ko :)])
(;W[bg];B[ae]
(;W[de];B[ab])
(;W[ab];B[bc]
(;W[ac];B[de])
(;W[de];B[ac]))))
(;W[bf];B[ba];W[ac];B[ab];W[ad];B[be];W[ae];B[de]))
(;W[cd];B[bd])
(;W[ca];B[ba];W[bd];B[bc]
(;W[cd];B[da])
(;W[ac];B[be];W[ae];B[bf]))
(;W[bf];B[ca];W[bd];B[cd];W[be];B[bc])
(;W[bc];B[bd]C[Only a ko.]))