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Dear all,

sorry for the late reply, at the moment I'm a bit busy finishing one

important calculation.

As Rolf wrote, Calc uses PowerSimplify which uses PowerExpand. The

latter can either assume that everything is real (default behaviour) or

use general expansion formulas if the arguments might be complex (which

we have now). Unfortunately, in this case PowerExpand doesn't take

$Assumptions into account.

I think that the simplest solution would be to make Calc and

PowerSimplify accept the Assumptions option which will be then passed to

PowerExpand. Then it will be up to the user to specify the assumptions.

As a workaround for now,

Sqrt[x - 1] // Calc // Simplify

returns the correct result, as Simplify always honors $Assumptions.

I'll fix this soon.

Cheers,

Vladyslav

Am 14.09.2015 um 10:58 schrieb Rolf Mertig:

*> This is due to me. Sorry.
*

*>
*

*> Somehwere internally PowerSimplify is used which assumes all variables are real. Maybe this assumption is not correct in general, of course. I mentioned this to Vladyslav and he will look into how to fix this. Sorry, but I have no time right now.
*

*>
*

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