(;GM[1]FF[4]SZ[19]
GN[After B1, White's marked stone is flipped, but doesn't get any true liberties as a result, so Black's move is illegal.]
PC[http://senseis.xmp.net/?LooseGoVariant]AP[GoWiki:2009]
DT[2012-02-13]
C[Diagram from http://senseis.xmp.net/?LooseGoVariant

After B1, White's marked stone is flipped, but doesn't get any true liberties as a result, so Black's move is illegal.]
PL[B]

AB[ih][kj][il]
AW[hi][ji][ij][hk][jk]
CR[ij]

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

;CR[ij]
)
