User blog comment:B1mb0w/Strong D Function Calculations/@comment-1605058-20150701125933/@comment-1605058-20150701134041

I have no idea how you get from $$n\uparrow\uparrow n$$ to $$\varepsilon_0$$. You need much more than $$n\uparrow\uparrow n$$ iterations of, say, $$f_\omega(n)$$, in order to get to $$f_{\varepsilon_0}(n)$$.