
theorem
  107 is prime
proof
  now
    107 = 2*53 + 1; hence not 2 divides 107 by NAT_4:9;
    107 = 3*35 + 2; hence not 3 divides 107 by NAT_4:9;
    107 = 5*21 + 2; hence not 5 divides 107 by NAT_4:9;
    107 = 7*15 + 2; hence not 7 divides 107 by NAT_4:9;
  end;
  then for n being Element of NAT st 1 < n & n*n <= 107 & n is prime
  holds not n divides 107 by XPRIMET1:8;
  hence thesis by NAT_4:14;
end;
