Re: Simplify puzzle
- To: mathgroup at smc.vnet.net
- Subject: [mg124670] Re: Simplify puzzle
- From: Peter Pein <petsie at dordos.net>
- Date: Mon, 30 Jan 2012 05:11:11 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <jfu0va$c92$1@smc.vnet.net>
Am 27.01.2012 12:14, schrieb Alan:
> Why does the first simplification below fail?
> (Each term succeeds!)
> Thanks,
> Alan Isaac
>
> In[205]:=
> myassumptions = a> 0&& b> 0&& c> 0&& 1> d> 0&& 1> e> 0;
> Simplify[a*b + c*(1 - d*(1 - e))> 0, Assumptions -> myassumptions]
> Simplify[a*b> 0, Assumptions -> myassumptions]
> Simplify[c*(1 - d*(1 - e))> 0, Assumptions -> myassumptions]
>
> Out[206]= a b + c + c d e> c d
>
> Out[207]= True
>
> Out[208]= True
>
I do not know why (Full)Simplify fails, but
FullSimplify @ ForAll[{a, b, c, d, e}, myassumptions,
a*b + c*(1 - d*(1 - e)) > 0]
does not