
theorem
  1487 is prime
proof
  now
    1487 = 2*743 + 1; hence not 2 divides 1487 by NAT_4:9;
    1487 = 3*495 + 2; hence not 3 divides 1487 by NAT_4:9;
    1487 = 5*297 + 2; hence not 5 divides 1487 by NAT_4:9;
    1487 = 7*212 + 3; hence not 7 divides 1487 by NAT_4:9;
    1487 = 11*135 + 2; hence not 11 divides 1487 by NAT_4:9;
    1487 = 13*114 + 5; hence not 13 divides 1487 by NAT_4:9;
    1487 = 17*87 + 8; hence not 17 divides 1487 by NAT_4:9;
    1487 = 19*78 + 5; hence not 19 divides 1487 by NAT_4:9;
    1487 = 23*64 + 15; hence not 23 divides 1487 by NAT_4:9;
    1487 = 29*51 + 8; hence not 29 divides 1487 by NAT_4:9;
    1487 = 31*47 + 30; hence not 31 divides 1487 by NAT_4:9;
    1487 = 37*40 + 7; hence not 37 divides 1487 by NAT_4:9;
  end;
  then for n being Element of NAT st 1 < n & n*n <= 1487 & n is prime
  holds not n divides 1487 by XPRIMET1:24;
  hence thesis by NAT_4:14;
end;
