
theorem MOD8:
  for a be odd square Integer holds a mod 8 = 1
  proof
    let a be odd square Integer;
    (a - (2*0+1)|^2) mod 8 + (1 mod (1+7)) = 1 mod (1 + 7) by NEWTON05:22; then
    ((a - 1)+1) mod 8 = 1 by NAT_D:66;
    hence thesis;
  end;
