(;GM[1]FF[4]SZ[19]
GN[Three stones prevention]
PC[http://senseis.xmp.net/?TwoSquares/Sandbox]AP[GoWiki:2009]
DT[2018-10-20]
C[Diagram from http://senseis.xmp.net/?TwoSquares/Sandbox

Three stones prevention]
PL[B]

AB[da][gb][ac][bc][cc][dc][ec]
AW[ba][ea][ab][bb][cb][db]
CR[da]

;B[eb]C[B1]MN[1]

;CR[da]
)
