So composition function is s(x) = ln(ln(x)) and natural domain is (1, +infinity)

So s(s(x)) = s(ln(ln(x)) = ln(ln(ln(ln(x)))) .

Is natural domain this function also (1,+infinity)????

What is the axes intercepts of y = s(s(x)) ???

I have tried assign x = 0 but my calculator can not find any solution .

Thank you.