(06/12/2022, 12:09 AM)tommy1729 Wrote:(06/12/2022, 12:07 AM)JmsNxn Wrote:(06/11/2022, 12:27 PM)tommy1729 Wrote: is x [s] f(x) = x
a degree of freedom ?
can we freely choose f(x) and work from there ??
regards
tommy1729
It is a degree of freedom yes, but I would write it using \(\varphi\). So that:
\[
x\,[s]_{\varphi} f(x) = x\\
\]
Then there is some \(\varphi\) where this statement is true (given that \(f\) is reasonably well behaved).
proof ??
I mean such that x [s] y is analytic in x , y , s to be clear.
and yes f(x) analytic ofcourse.
regards
tommy1729
Sure no problem:
\[
x = x[s]_{\varphi} f(x) = \exp^{\circ s}_{f(x)^{1/f(x)}}\left(\log^{\circ s}_{f(x)^{1/f(x)}}(x) + f(x) + \varphi\right)\\
\]
Take \(\log^{\circ s}_{f(x)^{1/f(x)}}\) on both sides, and cancel out the \(\log^{\circ s}_{f(x)^{1/f(x)}}(x)\): so that:
\[
f(x) + \varphi = 0\\
\]
And then writing
\[
\varphi(x) = -f(x)\\
\]
Gives you your answer.
So by construction:
\[
x [s]_{-f(x)} f(x) = x\\
\]
Not sure how that helps with anything, or what you are going to use it for. This also doesn't really help because you'd be asking for \(f(x) > e\), and I doubt that would really happen. There's no value \(f(x) > e\) such that \(x \langle s\rangle f(x) = x\). By nature of this looks like \(x + f(x) > x + e\) or in between \(x \cdot f(x) > x \cdot e\) which obviously can't equal \(x\). So these values would be beyond our purview.

