(;GM[1]FF[4]SZ[19]
GN[Black has a ko?]
PC[http://senseis.xmp.net/?RTGProblem12/Attempts]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?RTGProblem12/Attempts

Black has a ko?]
PL[B]

AB[ab][cb][eb][ac][cc]
AW[fb][hb][ec][fc][ad][bd][cd][dd]
LB[ea:a][bb:b]

;B[dc]C[B1]MN[1]
;W[ba]C[W2]MN[2]
;B[fa]C[B3]MN[3]
;W[ga]C[W4]MN[4]
;B[da]C[B5]MN[5]
;W[ca]C[W6]MN[6]

;LB[ea:a][bb:b]
)
