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Simplify and Abs

• To: mathgroup at smc.vnet.net
• Subject: [mg54602] Simplify and Abs
• From: Simon Anders <simon.anders at uibk.ac.at>
• Date: Thu, 24 Feb 2005 03:21:06 -0500 (EST)
• Organization: University of Innsbruck, Austria
• Sender: owner-wri-mathgroup at wolfram.com

Hi,

can it really be that this is already beyond Mathematica?

    In :=  FullSimplify[Abs[p - 1], p < 1 && p > 1/2]

    Out := Abs[-1 + p]

How do I make Matheamtica notice, that the assumptions constrain the 
argument of Abs[] to positive values?

Any suggestions how to treat these kinds of problems? Specifically, I 
have a list of products of absolute values of simple polynomials in p 
and I know that p is in the interval [0,1].

I would like to know whether the polynomials have constant sign over the 
interval so that the Abs[] can be removed. Can this be done automatically?

TIA
   Simon

• Follow-Ups:
  • Re: Simplify and Abs
    • From: Andrzej Kozlowski <akoz@mimuw.edu.pl>
  • Re: Simplify and Abs
    • From: DrBob <drbob@bigfoot.com>