02/24/2013, 10:56 AM
(This post was last modified: 02/24/2013, 10:56 AM by Balarka Sen.)

cosurgi Wrote:unless you can give me some formula for half-iterated logarithm and exp.

They are both defined as f(f(x)) = e^x and f(f(x)) = log(x), respectively. A closed form expression can be obtained for the former one in terms of natural tetration (base-e tetration) if I am not wrong but I don't know anything about the later one, unfortunately.