
theorem
  2887 is prime
proof
  now
    2887 = 2*1443 + 1; hence not 2 divides 2887 by NAT_4:9;
    2887 = 3*962 + 1; hence not 3 divides 2887 by NAT_4:9;
    2887 = 5*577 + 2; hence not 5 divides 2887 by NAT_4:9;
    2887 = 7*412 + 3; hence not 7 divides 2887 by NAT_4:9;
    2887 = 11*262 + 5; hence not 11 divides 2887 by NAT_4:9;
    2887 = 13*222 + 1; hence not 13 divides 2887 by NAT_4:9;
    2887 = 17*169 + 14; hence not 17 divides 2887 by NAT_4:9;
    2887 = 19*151 + 18; hence not 19 divides 2887 by NAT_4:9;
    2887 = 23*125 + 12; hence not 23 divides 2887 by NAT_4:9;
    2887 = 29*99 + 16; hence not 29 divides 2887 by NAT_4:9;
    2887 = 31*93 + 4; hence not 31 divides 2887 by NAT_4:9;
    2887 = 37*78 + 1; hence not 37 divides 2887 by NAT_4:9;
    2887 = 41*70 + 17; hence not 41 divides 2887 by NAT_4:9;
    2887 = 43*67 + 6; hence not 43 divides 2887 by NAT_4:9;
    2887 = 47*61 + 20; hence not 47 divides 2887 by NAT_4:9;
    2887 = 53*54 + 25; hence not 53 divides 2887 by NAT_4:9;
  end;
  then for n being Element of NAT st 1 < n & n*n <= 2887 & n is prime
  holds not n divides 2887 by XPRIMET1:32;
  hence thesis by NAT_4:14;
end;
