Replace each f in f^n to different variables

*To*: mathgroup at smc.vnet.net*Subject*: [mg125995] Replace each f in f^n to different variables*From*: Yi Wang <tririverwangyi at gmail.com>*Date*: Thu, 12 Apr 2012 02:33:19 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

Hi, all, I want to replace *each* f in f^n to a different variable, say f^n -> var1 * var2 * ... * varn Naively, if I try f^n /. f:>Unique[], Mathematica simply returns (a unique variable)^n, instead of the above behaviour. Is there a simple way to get the f's into different variables? Thanks! Yi PS: (1) I know there are ways to transform Power to a list by hand, and then do something in it. For example, Times[((f^3)[[1]]*Table[1, {(f^3)[[2]]}]) /. f :> Unique[]] However, eventually I will be dealing with a large expression, with all kinds of terms, instead of a single term. This method quickly becomes very complicated. (2) I want to do such "strange" things, because a product of functions in position space f(x)^n becomes F(k1)F(k2)...F(k_{n-1})F(-k1-k2...) in momentum space.

**Follow-Ups**:**Re: Replace each f in f^n to different variables***From:*Bob Hanlon <hanlonr357@gmail.com>