(;AW[da][db][dc][cd][ed][ce][af][bf][cf]AB[ca][cb][cc][bd][be]C[black to live ] (;B[ac] (;W[ae]C[CHOICE] (;B[bb] ;W[ad] (;B[aa]C[RIGHT ]) (;B[bc] ;W[aa])) (;B[ad] ;W[ab]) (;B[ab]CR[ab] ;W[ba]CR[ba] (;B[ad]CR[ad] ;W[bb]CR[bb]) (;B[bb]CR[bb] ;W[ad]CR[ad])) (;B[ba]CR[ba] ;W[ab]CR[ab] ;B[bb]CR[bb] ;W[ad]CR[ad]) (;B[aa]CR[aa] ;W[bb]CR[bb])) (;W[bb]CR[bb]C[CHOICE] (;B[ba]CR[ba] ;W[ab]CR[ab] (;B[ae]CR[ae]C[RIGHT]) (;B[bc]CR[bc] ;W[ae]CR[ae])) (;B[ab]CR[ab] ;W[ba]CR[ba] (;B[bc]CR[bc] ;W[ae]CR[ae]) (;B[ae]CR[ae] ;W[bc]CR[bc])))) (;B[bb] ;W[ac] (;B[ae] ;W[bc]) (;B[ab] ;W[ae] (;B[ad] ;W[bc]) (;B[bc]CR[bc] ;W[ad]CR[ad])) (;B[ad] ;W[ab] (;B[bc] ;W[aa]) (;B[aa] ;W[ba]C[Only ko.])) (;B[bc]CR[bc] ;W[ab]CR[ab] (;B[ae]CR[ae] ;W[aa]CR[aa]C[Black dies (the infamous 'bent four in the corner')]) (;B[aa]CR[aa] ;W[ba]CR[ba]C[Black does not have enough liberties to play A16, so this is only ko.]) (;B[ad]CR[ad] ;W[aa]CR[aa]C[Dead]))) (;B[ab] ;W[bc] (;B[ac] ;W[ad] ;B[bb] ;W[ae]) (;B[bb] ;W[ad] ;B[ac] ;W[ae]) (;B[ad]CR[ad] ;W[bb]CR[bb]) (;B[ba]CR[ba] ;W[ad]CR[ad])) (;B[bc]CR[bc] ;W[ab]CR[ab]C[No room left for two eyes.]) (;B[ae]CR[ae] ;W[bc]CR[bc]))