(;GM[1]FF[4]SZ[19]
GN[failure, B2 sets up ko]
PC[http://senseis.xmp.net/?GokyoShumyoSection4Problem45/Solution]AP[GoWiki:2009]
DT[2011-05-14]
C[Diagram from http://senseis.xmp.net/?GokyoShumyoSection4Problem45/Solution

failure, B2 sets up ko]
PL[W]

AB[bb][cb][cc][dc][ed][ce][ee][bf][cf]
AW[ab][bc][ec][fc][bd][cd][dd][be]

;W[eb]C[W1]MN[1]
;B[aa]C[B2]MN[2]
;W[ba]C[W3]MN[3]
;B[ca]C[B4]MN[4]

;
)
