(;GM[1]FF[4]SZ[19]
GN[Here W has the forcing move of W5 killing black in the corner]
PC[http://senseis.xmp.net/?GokyoShumyoSection3Problem79/Attempts]AP[GoWiki:2009]
DT[2011-01-06]
C[Diagram from http://senseis.xmp.net/?GokyoShumyoSection3Problem79/Attempts

Here W has the forcing move of W5 killing black in the corner]
PL[W]

AB[fo][go][dp][ep][hp][dq][hq][jq][cr][ir][ds]
AW[fp][gp][eq][gq][dr][er][gr][hr]

;W[cq]C[W1]MN[1]
;B[bq]C[B2]MN[2]
;W[cp]C[W3]MN[3]
;B[bs]C[B4]MN[4]
;W[co]C[W5]MN[5]
;B[dn]C[B6]MN[6]
;W[ar]C[W7]MN[7]

;
)
