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Re: Questions about assumptions

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  • Subject: [mg101787] Re: [mg101749] Questions about assumptions
  • From: "Elton Kurt TeKolste" <tekolste at>
  • Date: Fri, 17 Jul 2009 05:02:57 -0400 (EDT)
  • References: <>

Your assumption has been recorded globally.  Apparently, though,
Conjugate does not apply assumptions on its own -- you need to ask it to
do so.

In[1]:= $Assumptions = Element[g, Reals]

Out[1]= g \[Element] Reals

In[2]:= Conjugate[g]

Out[2]= Conjugate[g]

In[3]:= Simplify[Conjugate[g]]

Out[3]= g

On Thu, 16 Jul 2009 04:17 -0400, "Alexander Erlich"
<alexander.erlich at> wrote:
> Hello,
> I would like to make assumptions like e.g. Element[a,Reals] or b>0 or
> simlar ones global in order to avoid using Refine with long assumption
> lists every tome. For this purpose, I've found $Assumptions. But I
> encountered the following problem:
> In[5]:= $Assumptions = Element[g, Reals]
> Out[5]= g \[Element] Reals
> In[6]:= Conjugate[g]
> Out[6]= Conjugate[g]
> Why didn't Mathematica just return g?
> Maybe, there is a different, or even better way to make assumptions
> global to the whole notebook, so that they are considered
> automatically (and without Refine or similar)?
> Regards,
> Alexander

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