(;GM[1]FF[4]SZ[19]
GN[Block on the top side]
PC[http://senseis.xmp.net/?44DoubleLowApproachAttachExtend33Invasion]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?44DoubleLowApproachAttachExtend33Invasion

Block on the top side]
PL[B]

AB[dd][fd][fe]
AW[cc][fc][gd][cf]

;B[ec]C[B1]MN[1]
;W[gc]C[W2]MN[2]
;B[cd]C[B3]MN[3]
;W[bd]C[W4]MN[4]
;B[be]C[B5]MN[5]
;W[bc]C[W6]MN[6]
;B[ce]C[B7]MN[7]
;W[eb]C[W8]MN[8]
;B[dj]C[B9]MN[9]

;
)
