(;GM[1]FF[4]SZ[6:4]
GN[]
PC[http://senseis.xmp.net/?MathematicalTermForce]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?MathematicalTermForce

]
PL[B]

AB[ba][ca][bb][bc][cc][bd]
AW[da][ea][eb][dc][ec][fc][cd][dd]

;B[db]C[B1]MN[1]
;W[ab]C[W2]MN[2]
;B[ac]C[B3]MN[3]
;W[cb]C[W4]MN[4]

;
)
