(;AB[ba]AB[cb]AB[cc]AB[cd]AB[ce]AB[be]AW[bb]AW[bc]AW[db]AW[dc]AW[dd]AW[ee]AW[df]AW[cf]AW[bf]AW[bh]AW[fb]AP[goproblems]
(;B[ac]
(;W[ab];B[ad]C[Seki, best result for both.RIGHT])
(;W[ad]C[CHOICE]
(;B[ab];W[aa]
(;B[ab];W[ae]
(;B[bd]C[White was too greedy to allow a seki; but now Black lives with territory.RIGHT])
(;B[ac];W[aa])
(;B[ca];W[af])
(;B[aa];W[bd]))
(;B[bd];W[ca])
(;B[ac];W[ca])
(;B[ae];W[ca])
(;B[ca];W[ae]
(;B[ab];W[af])
(;B[ac];W[bd])
(;B[bd];W[ac])))
(;B[bd];W[ab]
(;B[ae];W[ac]C[One eye only.])
(;B[ca];W[ae]C[Black can only get one eye now.])
(;B[af];W[ac]C[Just one eye.]))
(;B[ae];W[ab]
(;B[bd];W[ac]C[One eye only.])
(;B[ca]C[Dead as it stands.])
(;B[af]C[Black remains dead.]))
(;B[ca];W[ae]
(;B[ab];W[aa]
(;B[ab])
(;B[ac];W[bd])
(;B[bd];W[ac]))
(;B[bd];W[ab]C[Black can get just one eye now.])
(;B[aa];W[bd]))
(;B[aa];W[ae]
(;B[bd];W[af]C[Just one eye.])
(;B[ab];W[af]C[Just one eye.]))))
(;B[ab];W[ac]
(;B[ad];W[aa]C[Ko, and Black has to find the first ko threat.])
(;B[ca];W[aa]
(;B[ae]C[];W[af]C[]
(;B[ab];W[da]C[This is a so-called 10000 year ko. Neither player can connect it. But White can kill Black if White has more ko threats.])
(;B[ad];W[ab]C[One eye...])
(;B[bd];W[ab]C[One eye!]))
(;B[ad];W[ab]C[That's just one eye.])
(;B[bd];W[ab]C[One eye only.])
(;B[ab]C[Hey!NOTTHIS]))
(;B[bd];W[aa]C[Ko])
(;B[ae];W[da]
(;B[ad];W[aa]C[Ko])
(;B[bd];W[aa]C[Ko])
(;B[ca];W[af]C[This is a so-called 10000 year ko. Neither player can connect it. But White can kill Black if White has more ko threats.])))
(;B[aa];W[ac]C[Just one eye.])
(;B[bd];W[ab]C[Just one eye.])
(;B[ca];W[ab]C[Just one eye.])
(;B[ad];W[ac]
(;B[ab];W[aa]C[Ko, and Black has to find the first ko threat.])
(;B[bd];W[ab]C[Well, dead.])
(;B[ca];W[ab]C[As a dodo.])
(;B[aa]C[Black is dead as it stands.])
(;B[ae];W[ab]C[Just one eye.]))
(;B[ae];W[ab]C[Only one eye.])
(;B[da];W[ab]C[Only one eye.])
(;B[af];W[ab]C[Only one eye.]))