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Re: Re: Simplify with NestedLessLess?

• To: mathgroup at smc.vnet.net
• Subject: [mg106560] Re: [mg106521] Re: [mg106487] Simplify with NestedLessLess?
• From: DrMajorBob <btreat1 at austin.rr.com>
• Date: Sat, 16 Jan 2010 06:12:26 -0500 (EST)
• References: <23979164.1263466810832.JavaMail.root@n11>
• Reply-to: drmajorbob at yahoo.com

In that case, use Limit... or NLimit... or Series.

Bobby

On Fri, 15 Jan 2010 02:19:16 -0600, Dave Bird <dbird at ieee.org> wrote:

> Thanks David. Good point.
>
> But, my example was just to illustrate in principle. My actual needed
> usage is in much more complicated expressions.
>
> Thanks again,
>
> Dave
>
> David Park wrote:
>> Why should it Simplify d? NestedLessLess has no built-in meaning. And  
>> even
>> if it did mean that b << a there is no reason that Mathematica should  
>> still
>> set b to zero. It doesn't even know if a and b are real positive. You  
>> will
>> have to set it to zero yourself.
>>
>> d /. b -> 0
>> a
>>
>> For more complicated expressions you might have to use Limit.
>>
>>
>> David Park
>> djmpark at comcast.net
>> http://home.comcast.net/~djmpark/
>>
>>
>>
>> From: dbird [mailto:dbird at ieee.org]
>>
>> Please excuse if this has been answered before, but I can't find it.
>>
>> Is there some way to do a Simplify with assumptions using a
>> NestedLessLess or something similar? For example:
>>
>> d=a+b
>> Simplify[d,NestedLessLess[a,b]]
>>
>> Answer is:
>> a+b
>>
>> Answer should be:
>> b
>>
>> Thanks,
>>
>> Dave
>>
>>
>>
>>
>


-- 
DrMajorBob at yahoo.com