(;GM[1]FF[4]SZ[19]
GN[1: all the white chains are unconditionally alive (the two black stones are necessary)]
PC[http://senseis.xmp.net/?BensonsDefinitionOfUnconditionalLife/Version20100208]AP[GoWiki:2009]
DT[2010-02-07]
C[Diagram from http://senseis.xmp.net/?BensonsDefinitionOfUnconditionalLife/Version20100208

1: all the white chains are unconditionally alive (the two black stones are necessary)]
PL[B]

AB[go][io]
AW[fn][gn][hn][in][jn][fo][jo][ko][lo][mo][fp][hp][jp][mp][hq][gr][hr][ir][gs][is]


;
)
