(;GM[1]FF[4]SZ[19]
GN[With BB in place Black can play B6, so W7 is not sente and White can't live unconditionally here. Ko next or B8 if White can't make an eye on the edge.]
PC[http://senseis.xmp.net/?BQM526]AP[GoWiki:2009]
DT[2010-11-15]
C[Diagram from http://senseis.xmp.net/?BQM526

With BB in place Black can play B6, so W7 is not sente and White can't live unconditionally here. Ko next or B8 if White can't make an eye on the edge.]
PL[W]

AB[cd][dd][ed]
AW[cc]
CR[ed]
LB[ac:a]

;W[bd]C[W1]MN[1]
;B[be]C[B2]MN[2]
;W[bb]C[W3]MN[3]
;B[db]C[B4]MN[4]
;W[dc]C[W5]MN[5]
;B[eb]C[B6]MN[6]
;W[cb]C[W7]MN[7]

;CR[ed]
LB[ac:a]
)
