for i1, i2, j1, j2 being Nat
for G being Go-board st 1 <= i1 & i1 <= len G & 1 <= i2 & i2 <= len G & 1 <= j1 & j1 <= j2 & j2 <= width G holds
(G * (i1,j1)) `2 <= (G * (i2,j2)) `2