4259 = (2 * 2129) + 1 ;
hence not 2 divides 4259 by NAT_4:9; :: thesis:
4259 = (3 * 1419) + 2 ;
hence not 3 divides 4259 by NAT_4:9; :: thesis:
4259 = (5 * 851) + 4 ;
hence not 5 divides 4259 by NAT_4:9; :: thesis:
4259 = (7 * 608) + 3 ;
hence not 7 divides 4259 by NAT_4:9; :: thesis:
4259 = (11 * 387) + 2 ;
hence not 11 divides 4259 by NAT_4:9; :: thesis:
4259 = (13 * 327) + 8 ;
hence not 13 divides 4259 by NAT_4:9; :: thesis:
4259 = (17 * 250) + 9 ;
hence not 17 divides 4259 by NAT_4:9; :: thesis:
4259 = (19 * 224) + 3 ;
hence not 19 divides 4259 by NAT_4:9; :: thesis:
4259 = (23 * 185) + 4 ;
hence not 23 divides 4259 by NAT_4:9; :: thesis:
4259 = (29 * 146) + 25 ;
hence not 29 divides 4259 by NAT_4:9; :: thesis:
4259 = (31 * 137) + 12 ;
hence not 31 divides 4259 by NAT_4:9; :: thesis:
4259 = (37 * 115) + 4 ;
hence not 37 divides 4259 by NAT_4:9; :: thesis:
4259 = (41 * 103) + 36 ;
hence not 41 divides 4259 by NAT_4:9; :: thesis:
4259 = (43 * 99) + 2 ;
hence not 43 divides 4259 by NAT_4:9; :: thesis:
4259 = (47 * 90) + 29 ;
hence not 47 divides 4259 by NAT_4:9; :: thesis:
4259 = (53 * 80) + 19 ;
hence not 53 divides 4259 by NAT_4:9; :: thesis:
4259 = (59 * 72) + 11 ;
hence not 59 divides 4259 by NAT_4:9; :: thesis:
4259 = (61 * 69) + 50 ;
hence not 61 divides 4259 by NAT_4:9; :: thesis:

end;

then for n being Element of NAT st 1 < n & n * n <= 4259 & n is prime holds
not n divides 4259 by XPRIMET1:36;
hence 4259 is prime by NAT_4:14; :: thesis: