(;SZ[19]AW[db]AW[cb]AW[cc]AW[cd]AW[be]AW[ad]AW[ae]AW[af]AW[fc]AW[hb]AW[jc]AB[ag]AB[bg]AB[bf]AB[ce]AB[df]AB[dd]AB[dc]AB[ec]AB[eb]AB[gb]AB[dj]C[Black to kill unconditionally. Japanese rules.]FF[1]GM[1]AP[Jago:Version 4.6]GN[my1]
(;B[bc];W[bb]
(;B[ab];W[bd])
(;B[ac];W[bd])
(;B[da];W[ca]
(;B[ac];W[bd])
(;B[ab];W[bd])))
(;B[bb];W[bc]
(;B[da];W[ca];B[ab];W[ba])
(;B[ca];W[da]))
(;B[da];W[bc]
(;B[ca];W[ba];B[ab];W[ac])
(;B[ba];W[ca])
(;B[ab];W[bb])
(;B[bb];W[ca];B[ab];W[ba]))
(;B[ca];W[da]
(;B[ba];W[bb])
(;B[ac];W[bd];B[ba];W[bb];B[ab];W[aa];B[ba]C[Seki.])
(;B[bb];W[bc]))
(;B[ba];W[bb]
(;B[ac];W[bd];B[ab];W[da])
(;B[ab];W[ac]))
(;B[ab]
(;W[da]C[CHOICE]
(;B[ac];W[bd]
(;B[ba];W[bb]C[Seki.])
(;B[bb];W[ba]))
(;B[ba];W[bb]
(;B[bc];W[bd];B[ac];W[aa];B[ab];W[ac])
(;B[ac];W[bd]C[Seki.])
(;B[ea];W[ac])
(;B[bd];W[bc];B[ac];W[aa]))
(;B[bb];W[ba]
(;B[ac];W[bd])
(;B[bc];W[bd]))
(;B[bc];W[bb]
(;B[ac];W[bd])
(;B[ba];W[bd];B[ac];W[aa];B[ab];W[ac]))
(;B[bd];W[bc]
(;B[ac];W[bd]
(;B[ba]C[RIGHT])
(;B[ea];W[ba]))
(;B[ba];W[ac])))
(;W[bb]C[CHOICE];B[ac];W[bd]
(;B[da];W[ca];B[aa]C[
Japanese bent four is unconditionally dead.RIGHT])
(;B[ba];W[da])))
(;B[ac];W[bd]
(;B[bc];W[bb])
(;B[ab];W[da]
(;B[ea];W[bb];B[ba]C[Seki.])
(;B[ba];W[bb]C[Seki.])
(;B[bb];W[ba]C[Seki.]))
(;B[ba];W[bb]
(;B[ab];W[da]C[Seki.])
(;B[da];W[ca]
(;B[ab]C[];W[aa]C[Wow, what a terrible ko. ;) Black to threaten first, and all those local ko threats for white!])
(;B[ea];W[ab]))
(;B[ca];W[da];B[ab];W[aa];B[ba]C[Seki.]))
(;B[bb];W[ba]
(;B[ab];W[da])
(;B[da];W[ab]C[Ko.]))
(;B[da];W[ab]
(;B[ca];W[ba])
(;B[bb];W[ba]C[Ko.])
(;B[ba];W[ca];B[bb];W[ea]
(;B[fb];W[bc])
(;B[fa];W[bc])
(;B[aa];W[fb]C[Oh no!])))
(;B[ca];W[da]
(;B[bb];W[ba];B[ab];W[bc])
(;B[ba];W[ab];B[bb];W[bc])
(;B[ab];W[ba];B[bb];W[bc]))
(;B[aa];W[ba]
(;B[da];W[ab])
(;B[ab];W[da];B[bb];W[bc]))))