theorem :: GOBOARD6:80

for G being Go-board st 1 < width G & 1 < len G holds
LSeg (((G * ((len G),1)) + |[1,(- 1)]|),(((1 / 2) * ((G * ((len G),1)) + (G * (((len G) -' 1),1)))) - |[0,1]|)) c= ((Int (cell (G,(len G),0))) \/ (Int (cell (G,((len G) -' 1),0)))) \/ {((G * ((len G),1)) - |[0,1]|)}