1489 = (2 * 744) + 1 ;
hence not 2 divides 1489 by NAT_4:9; :: thesis:
1489 = (3 * 496) + 1 ;
hence not 3 divides 1489 by NAT_4:9; :: thesis:
1489 = (5 * 297) + 4 ;
hence not 5 divides 1489 by NAT_4:9; :: thesis:
1489 = (7 * 212) + 5 ;
hence not 7 divides 1489 by NAT_4:9; :: thesis:
1489 = (11 * 135) + 4 ;
hence not 11 divides 1489 by NAT_4:9; :: thesis:
1489 = (13 * 114) + 7 ;
hence not 13 divides 1489 by NAT_4:9; :: thesis:
1489 = (17 * 87) + 10 ;
hence not 17 divides 1489 by NAT_4:9; :: thesis:
1489 = (19 * 78) + 7 ;
hence not 19 divides 1489 by NAT_4:9; :: thesis:
1489 = (23 * 64) + 17 ;
hence not 23 divides 1489 by NAT_4:9; :: thesis:
1489 = (29 * 51) + 10 ;
hence not 29 divides 1489 by NAT_4:9; :: thesis:
1489 = (31 * 48) + 1 ;
hence not 31 divides 1489 by NAT_4:9; :: thesis:
1489 = (37 * 40) + 9 ;
hence not 37 divides 1489 by NAT_4:9; :: thesis:

end;

then for n being Element of NAT st 1 < n & n * n <= 1489 & n is prime holds
not n divides 1489 by XPRIMET1:24;
hence 1489 is prime by NAT_4:14; :: thesis: