theorem Th2: :: GOBRD13:9
for i1, j1, j2 being Nat
for G1, G2 being Go-board st Values G1 c= Values G2 & [i1,j1] in Indices G1 & 1 <= j2 & j2 <= width G2 & G1 * (i1,j1) = G2 * (1,j2) holds
i1 = 1