(;GM[1]FF[4]SZ[19]
GN[If black has outside liberties, white can still get a ko]
PC[http://senseis.xmp.net/?ShapesRelatedToTheCarpentersSquare]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?ShapesRelatedToTheCarpentersSquare

If black has outside liberties, white can still get a ko]
PL[W]

AB[bb][db][dc][cd][dd]
AW[eb][gb][ec][ed][be][ce][de][ee][bg]
LB[da:b][cc:a]

;W[bc]C[W1]MN[1]
;B[bd]C[B2]MN[2]
;W[ba]C[W3]MN[3]
;B[ca]C[B4]MN[4]
;W[ab]C[W5]MN[5]

;LB[da:b][cc:a]
)
