
theorem
  5281 is prime
proof
  now
    5281 = 2*2640 + 1; hence not 2 divides 5281 by NAT_4:9;
    5281 = 3*1760 + 1; hence not 3 divides 5281 by NAT_4:9;
    5281 = 5*1056 + 1; hence not 5 divides 5281 by NAT_4:9;
    5281 = 7*754 + 3; hence not 7 divides 5281 by NAT_4:9;
    5281 = 11*480 + 1; hence not 11 divides 5281 by NAT_4:9;
    5281 = 13*406 + 3; hence not 13 divides 5281 by NAT_4:9;
    5281 = 17*310 + 11; hence not 17 divides 5281 by NAT_4:9;
    5281 = 19*277 + 18; hence not 19 divides 5281 by NAT_4:9;
    5281 = 23*229 + 14; hence not 23 divides 5281 by NAT_4:9;
    5281 = 29*182 + 3; hence not 29 divides 5281 by NAT_4:9;
    5281 = 31*170 + 11; hence not 31 divides 5281 by NAT_4:9;
    5281 = 37*142 + 27; hence not 37 divides 5281 by NAT_4:9;
    5281 = 41*128 + 33; hence not 41 divides 5281 by NAT_4:9;
    5281 = 43*122 + 35; hence not 43 divides 5281 by NAT_4:9;
    5281 = 47*112 + 17; hence not 47 divides 5281 by NAT_4:9;
    5281 = 53*99 + 34; hence not 53 divides 5281 by NAT_4:9;
    5281 = 59*89 + 30; hence not 59 divides 5281 by NAT_4:9;
    5281 = 61*86 + 35; hence not 61 divides 5281 by NAT_4:9;
    5281 = 67*78 + 55; hence not 67 divides 5281 by NAT_4:9;
    5281 = 71*74 + 27; hence not 71 divides 5281 by NAT_4:9;
  end;
  then for n being Element of NAT st 1 < n & n*n <= 5281 & n is prime
  holds not n divides 5281 by XPRIMET1:40;
  hence thesis by NAT_4:14;
end;
