IsPerfectPower

[James Wanless]

>
> Is this an algorithm for computing a^{1/b} which works just when a  
> is an
> integer (and b is an integer too)?
>
> We don't have, but that should be very simple to do using 2^t-adic
> arithmetic and lifting (increasing t).  Is that what ACCANT does?

I _think_ you're saying the same thing.
Basically it relies on gcd of 2^a-2 and a (ie FlittleT) to find a^(1/ 
b) [I think I've got that right]

>
> I guess a good implementation it would be less than a page of mpn  
> code.

If you're tentatively suggesting I write such - I'd be (sortof)  
prepared to have a go, though a) I'd be a little nervous of messing  
something up and b) you _might_ find by the time you've sorted me out  
it would have been quicker to write it yourself (eg I've never yet  
used 'patch', though maybe it's something I should learn! :) ). Anyway  
(to answer your question) I (too) believe the algorithm is very simple

>
> -- 
> Torbjörn

James