theorem Th6: :: GOBRD13:13

for i1, i2, j1, j2 being Nat
for G1, G2 being Go-board st Values G1 c= Values G2 & 1 <= i1 & i1 < len G1 & 1 <= j1 & j1 <= width G1 & 1 <= i2 & i2 < len G2 & 1 <= j2 & j2 <= width G2 & G1 * (i1,j1) = G2 * (i2,j2) holds
(G2 * ((i2 + 1),j2)) `1 <= (G1 * ((i1 + 1),j1)) `1