(;AW[ec]AW[dc]AW[fd]AW[gd]AB[ed]AB[fe]AB[gf]AB[de]AB[df]AB[cf]AW[ce]AW[cd]AB[if]AB[je]AB[jd]AB[ke]AB[kf]AB[ic]AB[jb]AB[hb]AW[jc]AW[kc]AW[kb]AW[lc]AW[kd]AW[le]AW[me]AW[mf]AW[mg]AW[gh]AW[ih]AW[jg]AW[jf]C[After the marked stone white should play ......]AW[he]AB[ie]AW[hf]AB[hd]AW[hg]AB[gc]TR[gc]AB[ch]AP[goproblems]
(;W[ja];B[ia]C[];W[ib];B[fc];W[ge];B[jb];W[fb]
(;B[gb];W[ib]C[Ko!RIGHT];B[eb]C[KO! but iF Black play the marked stone. Black die.];W[ha];B[db];W[cb];B[fa];W[da]C[RIGHT])
(;B[ka];W[gb]C[RIGHT]))
(;W[fb];B[fc];W[ge];B[gb]
(;W[eb];B[ia])
(;W[ja];B[eb]
(;W[db];B[fa])
(;W[ib];B[db])))
(;W[fc];B[fb];W[ja];B[ib]))