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global assumptions?? How far can I go?

• To: mathgroup at smc.vnet.net
• Subject: [mg53331] global assumptions?? How far can I go?
• From: Ron Griffin <ron-griffin at tamu.edu>
• Date: Thu, 6 Jan 2005 02:52:11 -0500 (EST)
• Sender: owner-wri-mathgroup at wolfram.com

I'm an economist whose accustomed to emphasizing the first orthant in a 
noncomplex world (positive, real prices; positive, real, quantities) so 
I really get flustered when Mathematica "pollutes" my output with "using inverse 
function" warnings and imaginary solutions.

Now I've "upgraded" to 5.1 from 4.2 and I find, as I expected from my 
experience during previous upgrades, that Mathematica is even more anal than it 
was before.  Hence, programs which ran well under 4.2 now are less 
functional because Mathematica is increasingly careful. 

So, how global can I go in telling Mathematica to assume that all the variables 
I create are real??  Must I list an assumption for each variable or each 
command??  Jees, now it won't even integrate 1/x^2 from 1 to t without 
dumping a bunch of worries on me.

ron

• Follow-Ups:
  • Re: global assumptions?? How far can I go?
    • From: Murray Eisenberg <murray@math.umass.edu>