reserve d,i,j,k,m,n,p,q,x,k1,k2 for Nat,
  a,c,i1,i2,i3,i5 for Integer;

theorem Th55:
  Fermat(n) > 2
proof
  set 2N = 2 |^ (2 |^ n);
  2N > 1 by Lm2;
  then 2N + 1 > 1 + 1 by XREAL_1:6;
  hence thesis;
end;
