(;GM[1]FF[4]SZ[19]
GN[Ko defense]
PC[http://senseis.xmp.net/?BeginnerMoveFunctionProblem3/Solution]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?BeginnerMoveFunctionProblem3/Solution

Ko defense]
PL[B]

AB[fp][jp][qp][fq][oq]
AW[cn][qn][dp][eq]
CR[cn][fp][eq]
LB[bo:c][do:b][cp:a]

;B[cq]C[B1]MN[1]
;W[dq]C[W2]MN[2]
;B[dr]C[B3]MN[3]
;W[er]C[W4]MN[4]
;B[br]C[B5]MN[5]
;W[bp]C[W6]MN[6]
;B[bq]C[B7]MN[7]
;W[ds]C[W8]MN[8]
;B[cs]C[B9]MN[9]
;W[es]C[W10]MN[10]

;CR[cn][fp][eq]
LB[bo:c][do:b][cp:a]
)
