
theorem
  2087 is prime
proof
  now
    2087 = 2*1043 + 1; hence not 2 divides 2087 by NAT_4:9;
    2087 = 3*695 + 2; hence not 3 divides 2087 by NAT_4:9;
    2087 = 5*417 + 2; hence not 5 divides 2087 by NAT_4:9;
    2087 = 7*298 + 1; hence not 7 divides 2087 by NAT_4:9;
    2087 = 11*189 + 8; hence not 11 divides 2087 by NAT_4:9;
    2087 = 13*160 + 7; hence not 13 divides 2087 by NAT_4:9;
    2087 = 17*122 + 13; hence not 17 divides 2087 by NAT_4:9;
    2087 = 19*109 + 16; hence not 19 divides 2087 by NAT_4:9;
    2087 = 23*90 + 17; hence not 23 divides 2087 by NAT_4:9;
    2087 = 29*71 + 28; hence not 29 divides 2087 by NAT_4:9;
    2087 = 31*67 + 10; hence not 31 divides 2087 by NAT_4:9;
    2087 = 37*56 + 15; hence not 37 divides 2087 by NAT_4:9;
    2087 = 41*50 + 37; hence not 41 divides 2087 by NAT_4:9;
    2087 = 43*48 + 23; hence not 43 divides 2087 by NAT_4:9;
  end;
  then for n being Element of NAT st 1 < n & n*n <= 2087 & n is prime
  holds not n divides 2087 by XPRIMET1:28;
  hence thesis by NAT_4:14;
end;
