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life and death
flag problem... (1) Well Constructed (1) Needs Fixing Invalid Duplicate
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Problem 13431
Created 2010-02-10
Source Problem 13428 by thornhead
Rating
Difficulty 1.9 kyu
Average Solve Time 88 secs
User Attempts
208 / 665
Solve Ratio Rating 4 kyu
rating history
Thornhead's solution was incorrect and his problem was deactivated, probably due to my claim that it had no possible solution path at all. Well, I could not be more wrong. So here goes, with apologies to Thornhead and thanks to all whose comments helped sharpen up this problem.
(;AB[ro]AB[qo]AB[qp]AB[pp]AB[oq]AB[or]AB[rq]AW[op]AW[np]AW[nq]AW[nr]AW[sq]AW[sn]AW[rn]AW[qn]AW[po]AW[pn]C[Black to find unconditional life.]AW[qr]AP[goproblems]
(;B[sr];W[ps]
(;B[rr];W[sp]
(;B[so])
(;B[qs];W[rs];B[so];W[os])
(;B[rs];W[so]
(;B[pq];W[os])
(;B[os];W[pq]))
(;B[pq];W[os]
(;B[so];W[rs])
(;B[rs];W[so])
(;B[pr];W[rs]))
(;B[pr];W[os])
(;B[qq];W[rs];B[os];W[ns]
(;B[pq];W[so])
(;B[ss];W[pq])
(;B[so];W[pq]))
(;B[os];W[pq]
(;B[so];W[rs])
(;B[rs];W[so])))
(;B[os];W[pq]
(;B[rr]
(;W[rs])
(;W[sp]
(;B[so];W[rs])
(;B[rs];W[so])))
(;B[sp];W[rr]))
(;B[pq];W[os]
(;B[rr];W[sp]
(;B[so];W[rs])
(;B[rs];W[so])
(;B[pr];W[rs]))
(;B[sp];W[rr]))
(;B[sp];W[rr]
(;B[os];W[pq])
(;B[qq];W[os])
(;B[pq];W[os])
(;B[pr];W[os])))
(;B[sp];W[rr]
(;B[sr];W[pr])
(;B[pq];W[ps];B[os];W[sr]
(;B[pr]
(;W[qs])
(;W[so]
(;B[qs];W[qq]
(;B[rp];W[ns])
(;B[rs];W[rp])
(;B[ss];W[rp]))
(;B[qq];W[rs]C[Double ko, Black dies];B[qs];W[rp]C[Double ko, Black dies])
(;B[rs];W[qq];B[rp];W[ns])
(;B[rp];W[qs])))
(;B[qq];W[rs]
(;B[pr];W[so]C[Double ko, Black dies];B[qs];W[rp]C[Double ko, Black dies])
(;B[so];W[ns]))
(;B[so];W[pr];B[rs];W[ns])
(;B[rs];W[so];B[pr];W[qq];B[rp];W[ns])))
(;B[pq];W[sp];B[so];W[rr];B[rp];W[sr];B[pr];W[ps];B[os];W[qs]C[CHOICE])
(;B[rr];W[ps]C[CHOICE]
(;B[sp];W[rs]
(;B[sr];W[pq]MA[qq]MA[so]C[RIGHT])
(;B[pq];W[os]
(;B[sr]C[RIGHT])
(;B[qq];W[sr]
(;B[ss];W[sr])
(;B[pr];W[qs];B[ss];W[sr]))
(;B[pr];W[sr]
(;B[ss];W[sr])
(;B[qq];W[qs];B[ss];W[sr]))
(;B[so];W[sr]
(;B[ss];W[sr])
(;B[qq];W[qs];B[ss];W[sr]))
(;B[ss];W[sr];B[ss];W[sr]))
(;B[qq];W[os]
(;B[sr]C[RIGHT])
(;B[pq];W[sr]
(;B[ss];W[sr])
(;B[pr];W[qs];B[ss];W[sr]))
(;B[pr];W[sr]
(;B[ss];W[sr]
(;B[qs]C[Just ko])
(;B[sq];W[pq])
(;B[pq];W[qs]))
(;B[qs]C[Just ko])
(;B[pq];W[qs];B[ss];W[sr]))
(;B[so];W[sr]))
(;B[os];W[pq]
(;B[qq];W[ns]
(;B[sr]C[RIGHT])
(;B[pr];W[pq]
(;B[sr]C[RIGHT])
(;B[so];W[sr]))
(;B[so];W[sr]))
(;B[sr]C[RIGHT])
(;B[so];W[sr]
(;B[qq];W[rp])
(;B[ss];W[sr]
(;B[qq];W[ns]
(;B[pr];W[pq])
(;B[sq];W[rp]))
(;B[sq];W[ns]
(;B[ss];W[qs])
(;B[qq];W[rp])))))
(;B[pr];W[os]
(;B[sr]C[RIGHT])
(;B[so];W[sr]
(;B[ss];W[sr])
(;B[qq];W[pq]))
(;B[pq];W[sr]
(;B[ss];W[sr])
(;B[qq])))
(;B[so];W[sr];B[os];W[pq]
(;B[qq];W[rp])
(;B[ss];W[sr]
(;B[qq];W[ns]
(;B[pr];W[pq])
(;B[sq];W[rp]))
(;B[sq];W[ns]
(;B[ss];W[qs])
(;B[qq])))))
(;B[rs];W[so]
(;B[sr];W[sp]
(;B[pq];W[os])
(;B[os];W[pq]))
(;B[os];W[pq]
(;B[sr];W[sp])
(;B[sp];W[qq]
(;B[rp];W[sr])
(;B[sr];W[rp])
(;B[qs];W[rp]))
(;B[qq];W[ns];B[sp];W[rp]C[Ko]))
(;B[pq];W[sp])
(;B[pr];W[os];B[sp];W[rp]C[Ko])
(;B[sp];W[rp]C[Ko]))
(;B[pq];W[so]
(;B[sp];W[rp]C[Ko])
(;B[sr];W[sp]
(;B[os]
(;W[rs])
(;W[rp]
(;B[pr];W[rs]C[Ko])
(;B[qq];W[rs])
(;B[rs];W[qq])))
(;B[rp];W[os])
(;B[pr];W[os])
(;B[rs];W[os]))
(;B[os];W[sr]
(;B[sp];W[rp]C[Ko])
(;B[pr];W[qs]
(;B[sp];W[rp]C[Ko])
(;B[rp];W[sp])
(;B[ss];W[sp])
(;B[rs];W[sp])
(;B[qq];W[sp]))
(;B[qq];W[sp])
(;B[rp];W[sp])
(;B[rs];W[sp])
(;B[qs];W[rs]
(;B[pr];W[qs]
(;B[sp];W[rp]C[Ko])
(;B[qq];W[sp])
(;B[rp];W[sp]))
(;B[rp];W[sp])
(;B[sp];W[rp]C[Ko])
(;B[qq];W[sp]))
(;B[ss];W[sp]))
(;B[rp];W[sp])
(;B[rs];W[sp])
(;B[pr];W[sp]))
(;B[os];W[pq]
(;B[sr]
(;W[rs])
(;W[sp]))
(;B[sp];W[qq]
(;B[rs];W[so]
(;B[rp];W[sr])
(;B[sr];W[rp])
(;B[qs];W[rp]))
(;B[sr];W[so]
(;B[rp];W[rs])
(;B[rs];W[rp]))
(;B[so];W[rp])
(;B[rp];W[rs]))
(;B[qq];W[ns];B[sp];W[rs];B[sr]C[RIGHT])
(;B[rs];W[so]
(;B[sr];W[sp])
(;B[sp];W[qq]
(;B[rp];W[sr])
(;B[sr];W[rp])
(;B[qs];W[rp]))
(;B[qq];W[ns];B[sp];W[rp]C[Ko])))
(;B[pr];W[os]
(;B[rs];W[so];B[sp];W[rp]C[Ko])
(;B[sp]
(;W[so]
(;B[sr];W[qq]
(;B[rp];W[rs])
(;B[rs];W[pq];B[rp]C[RIGHT])
(;B[pq];W[rp])
(;B[qs];W[rs]))
(;B[rp];W[rs])
(;B[qq];W[pq];B[sr]C[RIGHT])
(;B[pq];W[rp]C[Ko])
(;B[rs];W[rp]C[Ko]))
(;W[rs]
(;B[sr]C[RIGHT])
(;B[so];W[sr]
(;B[ss];W[sr])
(;B[qq];W[pq]))
(;B[pq];W[sr])))
(;B[so];W[rs]
(;B[sp];W[sr]
(;B[ss];W[sr])
(;B[qq];W[pq]))
(;B[sr];W[sp]))
(;B[sr];W[sp])
(;B[pq];W[rs])
(;B[qq];W[rs]
(;B[sr];W[sp]
(;B[so];W[pq])
(;B[qs]C[Ko])
(;B[ss];W[pq])
(;B[pq];W[qs]))
(;B[sp];W[sr]
(;B[ss];W[sr]
(;B[qs]C[Just ko])
(;B[sq];W[pq])
(;B[pq];W[qs]))
(;B[qs]C[Just ko])
(;B[pq]))
(;B[qs]C[Ko])))
(;B[sr];W[sp]
(;B[so])
(;B[qs];W[rs];B[so];W[os])
(;B[rs];W[so]
(;B[pq];W[os])
(;B[os];W[pq]))
(;B[pq];W[os]
(;B[so];W[rs])
(;B[rs];W[so])
(;B[pr];W[rs]))
(;B[pr];W[os])
(;B[qq];W[rs];B[os];W[ns]
(;B[pq];W[so])
(;B[ss];W[pq])
(;B[so];W[pq]))
(;B[os];W[pq]
(;B[so];W[rs])
(;B[rs];W[so])))
(;B[rp];W[rs];B[os];W[pq])
(;B[so];W[rs]
(;B[sr];W[sp];B[os];W[pq])
(;B[os];W[pq];B[sp];W[sr]
(;B[qq];W[rp])
(;B[ss];W[sr]
(;B[qq];W[ns]
(;B[pr];W[pq])
(;B[sq];W[rp]))
(;B[sq];W[ns]
(;B[ss];W[qs])
(;B[qq])))))
(;B[qq];W[rs]
(;B[pr];W[os]
(;B[sr];W[sp]
(;B[so];W[pq])
(;B[qs]C[Ko])
(;B[ss];W[pq])
(;B[pq];W[qs]))
(;B[sp])
(;B[qs]C[Ko]))
(;B[sp];W[os]
(;B[sr]C[RIGHT])
(;B[pq])
(;B[pr];W[sr]
(;B[ss];W[sr]
(;B[qs]C[Just ko])
(;B[sq];W[pq])
(;B[pq];W[qs]))
(;B[qs]C[Just ko])
(;B[pq]))
(;B[so];W[sr]))
(;B[sr];W[sp];B[os];W[ns]
(;B[pq];W[so])
(;B[ss];W[pq])
(;B[so];W[pq]))
(;B[os]
(;W[ns]
(;B[sp];W[pq];B[sr]C[RIGHT])
(;B[pq];W[so]
(;B[pr];W[qs]
(;B[sr];W[sp])
(;B[sp];W[rp]C[Ko])
(;B[ss];W[qs];B[sp];W[rp]C[Ko]))
(;B[sr];W[sp])
(;B[sp];W[rp]C[Ko]))
(;B[sr];W[sp]
(;B[pq];W[so])
(;B[ss];W[pq])
(;B[so];W[pq])))
(;W[sp];B[pr]))))
(;B[ps];W[rr]
(;B[sp];W[sr]
(;B[so];W[pq])
(;B[pq];W[so]
(;B[rp];W[pr])
(;B[qs];W[qq];B[rp];W[rs]))
(;B[qq];W[so]C[Ko]))
(;B[so];W[pq]
(;B[qq];W[pr])
(;B[pr];W[qq]))
(;B[qq];W[sp];B[so];W[pr]
(;B[pq];W[qs]
(;B[ns];W[ms])
(;B[os];W[ns]))
(;B[sr];W[ss]
(;B[pq];W[qs])
(;B[qs];W[pq])
(;B[os];W[pq])))
(;B[pr];W[sp];B[so];W[qq]
(;B[pq];W[rp])
(;B[rp];W[pq]))
(;B[pq];W[sp];B[so];W[qs])
(;B[qs];W[sp];B[so];W[pq]
(;B[pr];W[qq])
(;B[qq];W[rp])
(;B[rp];W[qq])
(;B[sr];W[ss])
(;B[rs];W[pr]))
(;B[rp];W[pq]))
(;B[so];W[rr]
(;B[sp];W[pq])
(;B[pq];W[sp];B[rp];W[sr];B[pr];W[ps];B[os];W[qs]C[CHOICE])
(;B[pr];W[qq]
(;B[rp];W[pq])
(;B[sp];W[pq];B[sr];W[ps])
(;B[pq];W[rp]
(;B[sp];W[rq])
(;B[qs];W[sp])))
(;B[qq];W[pr])
(;B[os];W[pq])
(;B[ps];W[pq]
(;B[qq];W[pr])
(;B[pr];W[qq])))
(;B[pr];W[rr]
(;B[sp];W[sr]
(;B[so];W[qq]
(;B[pq];W[ps]
(;B[os];W[rs];B[qs];W[rp]C[Black dies with double ko])
(;B[qs];W[rs];B[os]C[Black dies with double ko]))
(;B[qs];W[pq]))
(;B[qq];W[so]C[Ko])
(;B[pq];W[so]
(;B[qs];W[qq]
(;B[rp];W[os])
(;B[rs];W[rp]))
(;B[qq];W[ps]
(;B[os];W[rs];B[qs];W[rp]C[Double ko, Black dies])
(;B[qs];W[rs];B[os]C[Black dies with double ko]))
(;B[rp];W[qs]))
(;B[qs];W[qq]
(;B[pq];W[so]
(;B[rp];W[os])
(;B[rs];W[rp]))
(;B[so];W[pq])
(;B[rs];W[so]))
(;B[rp];W[pq];B[qq];W[so]))
(;B[qq];W[sp]
(;B[so];W[sr]
(;B[qs];W[rp]
(;B[pq];W[os])
(;B[rs];W[pq]))
(;B[pq];W[qs]))
(;B[sr];W[ss];B[so];W[qs])
(;B[qs];W[so]))
(;B[so];W[qq]
(;B[rp];W[pq])
(;B[sp];W[pq];B[sr];W[ps])
(;B[pq];W[rp]
(;B[sp];W[rq])
(;B[qs];W[sp])))
(;B[sr];W[sp]
(;B[so];W[ss]
(;B[rp];W[pq]
(;B[sr];W[ps]
(;B[qq];W[os])
(;B[rs];W[os])
(;B[qs];W[os])
(;B[os];W[ns]))
(;B[qq];W[pq]))
(;B[qq];W[qs])
(;B[qs];W[qq]))
(;B[qq];W[ss];B[so];W[qs])
(;B[ss];W[so])
(;B[rp];W[so])
(;B[qs];W[so])))
(;B[os];W[rr]
(;B[sp];W[pq])
(;B[pq];W[sp]
(;B[so])
(;B[sr];W[ss]
(;B[so];W[qs])
(;B[qs];W[so])))
(;B[pr];W[qq];B[sp];W[pq];B[sr];W[ns])
(;B[so];W[pq])
(;B[qq];W[pr]
(;B[pq];W[sp]
(;B[so];W[sr])
(;B[sr];W[ss];B[so];W[ps]))
(;B[sp];W[pq])))
(;B[qs];W[rr]
(;B[pr];W[sp]
(;B[so];W[qq]
(;B[rp];W[pq])
(;B[pq];W[rp])
(;B[sr];W[ss])
(;B[rs];W[rp]))
(;B[sr];W[ss]
(;B[so];W[qq])
(;B[rp];W[so])
(;B[qq];W[so]))
(;B[qq];W[so])
(;B[rs];W[sr];B[so];W[qq]
(;B[pq];W[rp])
(;B[rp];W[pq])))
(;B[pq];W[sp]
(;B[so]
(;W[sr]
(;B[qq];W[rs])
(;B[rs];W[qq])
(;B[pr];W[rs]))
(;W[ps];B[pr]))
(;B[sr];W[so]
(;B[rs];W[ps])
(;B[ps];W[ss])))
(;B[sp];W[pr]
(;B[pq];W[os])
(;B[ps];W[pq])
(;B[os];W[pq]
(;B[sr];W[ns])
(;B[ps];W[ns])
(;B[rs];W[ns]))
(;B[sr];W[pq])
(;B[qq];W[pq])))
(;B[rs];W[rr]
(;B[sp];W[sr]
(;B[pr];W[qq]
(;B[qs];W[so])
(;B[so];W[pq]))
(;B[qq];W[pr])
(;B[pq];W[qq]
(;B[rp];W[qs])
(;B[pr];W[so]
(;B[rp];W[os])
(;B[qs];W[rp]))
(;B[qs];W[so]
(;B[rp];W[os])
(;B[pr];W[rp])))
(;B[so];W[pq]))
(;B[qq];W[pr]
(;B[ps];W[pq])
(;B[pq];W[os])
(;B[os];W[pq])
(;B[sp];W[pq]))
(;B[pr];W[qq];B[sp];W[sr]
(;B[qs])
(;B[so];W[pq]))
(;B[pq];W[sp]
(;B[sr];W[so]
(;B[qs];W[ps])
(;B[pr];W[qs])
(;B[qq];W[qs]))
(;B[so];W[sr];B[ps];W[qs])))
(;B[qq];W[rr]
(;B[sp];W[pr])
(;B[pr];W[sp]
(;B[so];W[sr]
(;B[qs];W[rp]
(;B[pq];W[os])
(;B[rs];W[pq]))
(;B[pq];W[qs]))
(;B[sr];W[ss];B[so];W[qs])
(;B[qs];W[so]))
(;B[sr];W[pr])
(;B[os];W[pr]
(;B[pq];W[sp]
(;B[so];W[sr])
(;B[sr];W[ss];B[so];W[ps]))
(;B[sp];W[pq]))
(;B[ps];W[sp];B[so];W[pr]
(;B[pq];W[qs]
(;B[ns];W[ms])
(;B[os];W[ns]))
(;B[sr];W[ss]
(;B[pq];W[qs])
(;B[qs];W[pq])
(;B[os];W[pq])))))
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