On Tuesday, March 18, 2014 8:20:31 PM UTC+4, Harsh Gupta wrote:
>
> We will have to be "very" careful while rewriting the solvers. I just came 
> across another of Professor Fateman's paper which describes why the 
> solution of z**w == y for z isn't simply y**(1/w).
>
> http://www.cs.berkeley.edu/~fateman/papers/y=z2w.pdf
>
> Sadly we doing it wrong.
>
> We are also wrongly simplifying y - (y**(1/(1 + I)))**(1 + I) as 0.
>
> In [58]: f
>
> Out[58]: y - (y**(1/(1 + I)))**(1 + I)
>
>
> In [59]: simplify(f)
>
> Out[59]: 0
>

Indeed (e.g. y=-10000 + 4000*I).  Looks a bug somewhere in powsimp().  It 
doesn't look as a new for me, so maybe it was already reported.

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