theorem Th4: :: GOBOARD5:4

for i, j1, j2 being Nat
for G being Matrix of (TOP-REAL 2) st G is Y_increasing-in-line & 1 <= j1 & j1 < j2 & j2 <= width G & 1 <= i & i <= len G holds
(G * (i,j1)) `2 < (G * (i,j2)) `2