4643 = (2 * 2321) + 1 ;
hence not 2 divides 4643 by NAT_4:9; :: thesis:
4643 = (3 * 1547) + 2 ;
hence not 3 divides 4643 by NAT_4:9; :: thesis:
4643 = (5 * 928) + 3 ;
hence not 5 divides 4643 by NAT_4:9; :: thesis:
4643 = (7 * 663) + 2 ;
hence not 7 divides 4643 by NAT_4:9; :: thesis:
4643 = (11 * 422) + 1 ;
hence not 11 divides 4643 by NAT_4:9; :: thesis:
4643 = (13 * 357) + 2 ;
hence not 13 divides 4643 by NAT_4:9; :: thesis:
4643 = (17 * 273) + 2 ;
hence not 17 divides 4643 by NAT_4:9; :: thesis:
4643 = (19 * 244) + 7 ;
hence not 19 divides 4643 by NAT_4:9; :: thesis:
4643 = (23 * 201) + 20 ;
hence not 23 divides 4643 by NAT_4:9; :: thesis:
4643 = (29 * 160) + 3 ;
hence not 29 divides 4643 by NAT_4:9; :: thesis:
4643 = (31 * 149) + 24 ;
hence not 31 divides 4643 by NAT_4:9; :: thesis:
4643 = (37 * 125) + 18 ;
hence not 37 divides 4643 by NAT_4:9; :: thesis:
4643 = (41 * 113) + 10 ;
hence not 41 divides 4643 by NAT_4:9; :: thesis:
4643 = (43 * 107) + 42 ;
hence not 43 divides 4643 by NAT_4:9; :: thesis:
4643 = (47 * 98) + 37 ;
hence not 47 divides 4643 by NAT_4:9; :: thesis:
4643 = (53 * 87) + 32 ;
hence not 53 divides 4643 by NAT_4:9; :: thesis:
4643 = (59 * 78) + 41 ;
hence not 59 divides 4643 by NAT_4:9; :: thesis:
4643 = (61 * 76) + 7 ;
hence not 61 divides 4643 by NAT_4:9; :: thesis:
4643 = (67 * 69) + 20 ;
hence not 67 divides 4643 by NAT_4:9; :: thesis:

end;

then for n being Element of NAT st 1 < n & n * n <= 4643 & n is prime holds
not n divides 4643 by XPRIMET1:38;
hence 4643 is prime by NAT_4:14; :: thesis: