Re: Questions about assumptions
- To: mathgroup at smc.vnet.net
- Subject: [mg101797] Re: [mg101749] Questions about assumptions
- From: "David Park" <djmpark at comcast.net>
- Date: Fri, 17 Jul 2009 05:04:48 -0400 (EDT)
- References: <5024475.1247748242478.JavaMail.root@n11>
I think that $Assumptions is only picked up by expressions that take the Assumptions option. It does not automatically get spread to everywhere. For example, Simplify takes the Assumptions so: $Assumptions = Element[g, Reals]; Conjugate[g] // Simplify g Conjugate[f] // Simplify Conjugate[f] David Park djmpark at comcast.net http://home.comcast.net/~djmpark/ From: Alexander Erlich [mailto:alexander.erlich at gmail.com] 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