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Re: unable to FullSimplify

• To: mathgroup at smc.vnet.net
• Subject: [mg65872] Re: unable to FullSimplify
• From: "Vladimir" <vladimir347 at yahoo.com>
• Date: Thu, 20 Apr 2006 05:14:55 -0400 (EDT)
• References: <200604160545.BAA07958@smc.vnet.net> <200604181056.GAA14321@smc.vnet.net> <e24uhn$5s7$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Andrzej Kozlowski wrote:
> Well, it seems to me that you are expecting too much.

Well, yes, considering the internal simplification and
related code is supposedly thousands of pages long.

> x + x^4 + 4*x^5 + 6*x^6 + 4*x^7 + x^8
>
> there are just too many different groupings and rearrangements that
> would have to be tried to get to a simpler form.

According to documentation, "FullSimplify effectively has to try
combining every part of an expression with every other".

> Sometimes the only
> way to transform an expression to a simpler form is by first
> transforming it to a more complex one

I'm sure FullSimplify can be improved without the need
for such complexification steps. For example:

In[]:= subdivide[a_ + b_] := FullSimplify[a] + FullSimplify[b];
         FullSimplify[Expand[x + (x + x^2)^4],
           TransformationFunctions -> {Automatic, subdivide}]

Out[]= x + x^4*(1 + x)^4

--
Vladimir

• Follow-Ups:
  • Re: Re: unable to FullSimplify
    • From: Andrzej Kozlowski <akoz@mimuw.edu.pl>

• References:
  • unable to FullSimplify
    • From: vladimir347@yahoo.com
  • Re: unable to FullSimplify
    • From: "Vladimir" <vladimir347@yahoo.com>