
theorem th0b:
for n being Nat st n >= 3 holds n +` n in exp(2,n)
proof
let n be Nat;
assume AS: n >= 3;
n +` n = n + n by th0a; then
n +` n < 2|^n by AS,th0n; then
n +` n in 2|^n by th0k;
hence thesis by th0e;
end;
