User blog comment:B1mb0w/Strong D Function/@comment-1605058-20150624061803/@comment-1605058-20150701151629

Let me attract your attention to this comment of mine. This is a formal proof of the fact that there is no way for your notation, even with arbitrary number of variables, let alone just 3, to achieve the growth rate of $$f_{\varepsilon_0}(n)$$.