global real variables
- To: mathgroup at smc.vnet.net
- Subject: [mg22019] global real variables
- From: Naum Phleger <naum at cava.physics.ucsb.edu>
- Date: Thu, 10 Feb 2000 02:26:07 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
I asked a dumb question a few weeks ago about making variables real and
found that Mathematica 4 took care of this better. I have been using it
since. I still have a couple of problems with it though. First, I can have
variables be treated as real by using the assumption Element[x,Reals] in a
simplify command, but I want x to be real in all commands so I don't have to
keep using Simplify each time I want x to be recognized as real. Second,
even this doesn't seem to work quite right. Here is what I mean.
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