Re: global real variables

*To*: mathgroup at smc.vnet.net*Subject*: [mg22039] Re: global real variables*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Fri, 11 Feb 2000 02:38:20 -0500 (EST)*Organization*: Universitaet Leipzig*References*: <87trds$5o3@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi, my Mathematica 4.0.1 reply for FullSimplify[Conjugate[x + x*p^-1], Element[{x, p}, Reals]] (1 + p^(-1))*x But I agree that the Element relation should be an attribute to a symbol. The best thing is to make a global variable $mydomains={Element[{x,p},Reals] && Element[{i,j,k},Integers]} and use Simplify[expr,$mydomains] during your calculation. Manly to avoid that you simplify with the assumption x is real and two steps later you forgot this. Hope that helps Jens > > Say I have tow var.s, x and p. Both are real so I can do this. > > Simplify[ Conjugate[ x ] , Element[ x , Reals ] ] ----> x > > amd I get the same thing for p, but it stops working if I have functions of > x and p, for instance I get > > Simplify[ Conjugate[ x + x * p^-1 ] , Element[ {x,p} , Reals ] ] ----> > > Conjugate[ x + x * p^-1 ] > > It works if I use FullSimplify AND put p^-1 into the list of variables > that I want to have real. How can I get around this without listing every > negative power of every variable and wasting time with FullSimplify. Thanks > for any help. Thanks. > > -NAUM