6917 = (2 * 3458) + 1 ;
hence not 2 divides 6917 by NAT_4:9; :: thesis:
6917 = (3 * 2305) + 2 ;
hence not 3 divides 6917 by NAT_4:9; :: thesis:
6917 = (5 * 1383) + 2 ;
hence not 5 divides 6917 by NAT_4:9; :: thesis:
6917 = (7 * 988) + 1 ;
hence not 7 divides 6917 by NAT_4:9; :: thesis:
6917 = (11 * 628) + 9 ;
hence not 11 divides 6917 by NAT_4:9; :: thesis:
6917 = (13 * 532) + 1 ;
hence not 13 divides 6917 by NAT_4:9; :: thesis:
6917 = (17 * 406) + 15 ;
hence not 17 divides 6917 by NAT_4:9; :: thesis:
6917 = (19 * 364) + 1 ;
hence not 19 divides 6917 by NAT_4:9; :: thesis:
6917 = (23 * 300) + 17 ;
hence not 23 divides 6917 by NAT_4:9; :: thesis:
6917 = (29 * 238) + 15 ;
hence not 29 divides 6917 by NAT_4:9; :: thesis:
6917 = (31 * 223) + 4 ;
hence not 31 divides 6917 by NAT_4:9; :: thesis:
6917 = (37 * 186) + 35 ;
hence not 37 divides 6917 by NAT_4:9; :: thesis:
6917 = (41 * 168) + 29 ;
hence not 41 divides 6917 by NAT_4:9; :: thesis:
6917 = (43 * 160) + 37 ;
hence not 43 divides 6917 by NAT_4:9; :: thesis:
6917 = (47 * 147) + 8 ;
hence not 47 divides 6917 by NAT_4:9; :: thesis:
6917 = (53 * 130) + 27 ;
hence not 53 divides 6917 by NAT_4:9; :: thesis:
6917 = (59 * 117) + 14 ;
hence not 59 divides 6917 by NAT_4:9; :: thesis:
6917 = (61 * 113) + 24 ;
hence not 61 divides 6917 by NAT_4:9; :: thesis:
6917 = (67 * 103) + 16 ;
hence not 67 divides 6917 by NAT_4:9; :: thesis:
6917 = (71 * 97) + 30 ;
hence not 71 divides 6917 by NAT_4:9; :: thesis:
6917 = (73 * 94) + 55 ;
hence not 73 divides 6917 by NAT_4:9; :: thesis:
6917 = (79 * 87) + 44 ;
hence not 79 divides 6917 by NAT_4:9; :: thesis:
6917 = (83 * 83) + 28 ;
hence not 83 divides 6917 by NAT_4:9; :: thesis:

end;

then for n being Element of NAT st 1 < n & n * n <= 6917 & n is prime holds
not n divides 6917 by XPRIMET1:46;
hence 6917 is prime by NAT_4:14; :: thesis: