(;AB[ab]AW[ac]AW[bc]AW[bb]AW[ba]AW[cb]AW[dc]AW[ec]AW[fb]AB[ga]AB[gb]AB[gc]AB[fc]AB[ed]AB[dd]AB[cd]AB[cc]AB[bd]C[Taken from Cho Chikun's Encyclipedia of 1,000 Elementary Life and Death Problems. B to kill. Feel free to flag and add variations.CHOICE]AP[goproblems]
(;B[da];W[db]C[]
(;B[ea];W[eb];B[fa]C[W is dead. :)RIGHT])
(;B[fa]C[RIGHT]))
(;B[ea]C[];W[da])
(;B[eb];W[db];B[ea];W[da]C[W is alive. :(])
(;B[db];W[eb];B[da];W[ca]
(;B[fa];W[ea];B[db];W[da]C[W is alive. :(])
(;B[ea];W[fa]C[W is alive. :(])))