theorem Th23: :: JORDAN1B:23

for G being Go-board
for i, m, n being Nat
for p being Point of (TOP-REAL 2) st 1 <= i & i < len G & 1 <= m & m <= len G & 1 <= n & n <= width G & p in cell (G,i,(width G)) & p `2 = (G * (m,n)) `2 holds
width G = n