(;GM[1]FF[4]SZ[9]
GN[Option 2: invading]
PC[http://senseis.xmp.net/?RobertsVsCasey]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?RobertsVsCasey

Option 2: invading]
PL[B]

LB[dd:a][ce:b]

;B[gc]C[B1]MN[1]
;W[cg]C[W2]MN[2]
;B[fg]C[B3]MN[3]
;W[dc]C[W4]MN[4]

;LB[dd:a][ce:b]
)
