(;GM[1]FF[4]CA[UTF-8]SZ[19]AB[pb][pc][qc][rc][pr][pq][qq][rq][rp][bp][bq][cq][dq][dr][bd][cc][bc][dc][db][eb]AW[ob][mb][oc][od][pd][qd][rd][rf][ro][rm][qp][pp][qo][op][oq][or][mr][er][fr][eq][ep][dp][cp][co][bo][bm][be][ce][cd][dd][ed][ec][fc][fb][hb][bg]C[Upper right: black to play
Lower right: black to play
Lower left: white to play
Upper left: white to play

Play tengen to see the solutions];B[jj];W[kj](;B[pa];W[sc];B[sb];W[ra]C[Dead])(;B[rb];W[sc];B[qa];W[sb]C[Dead, only one real eye])(;B[kk];W[jk](;B[rs]C[the vital point];W[sr];B[rr]TR[qr][ss]C[two eyes. White is alive])(;B[rr]C[Another vital point?];W[qs];B[ps];W[rs];B[sp];W[sr]C[Seki])(;B[kl](;W[ap](;B[aq];W[ds];B[cs];W[br]C[Dead])(;B[br];W[cs];B[ds];W[bs];B[aq];W[as]C[Dead])(;B[bs];W[ar];B[aq];W[ds]C[Dead]))(;W[br];B[ar];W[bs];B[ds];W[ap]C[one eye...])(;W[ik];B[ji]TR[ca]SQ[ca](;W[ea];B[ba];W[ab];B[bb]TR[cb][aa]C[Alive])(;W[ad];B[bb];W[ca];B[ba]TR[aa][cb]C[Alive])(;W[bb];B[ab];W[ca];B[cb];W[ba];B[ad]C[Two eyes, no ko]TR[ac][aa][ca][ba][bb])(;W[ca];B[ab];W[bb];B[cb]C[no ko, white is alive])))))