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MathGroup Archive 1997

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Re: Re: Just another bug in MMA 3.0

  • To: mathgroup at smc.vnet.net
  • Subject: [mg7520] Re: [mg7491] Re: [mg7431] Just another bug in MMA 3.0
  • From: Paulo Mouat <mouat at mail.telepac.pt>
  • Date: Tue, 10 Jun 1997 23:17:53 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

Kai Koehler wrote:
> E.g. what do you think about the following quite serious bug, which I
> mailed Wolfram support on april 4th:
> 
> Sum[Sum[Log[Log[k+j]],{k,1,n}],{j,1,5}]
> 
> gives
> 
> 5*Sum[Log[Log[k + j]], {k, 1, n}].
> 
> Many other people verified this bug on various machines.

If you want to do a multiple sum, the input should read

Sum[Log[Log[k+j]],{k,1,n},{j,1,5}]

What you have typed is a simple sum over k with a function that has an
unknown j.  The j on the outer Sum is a dummy variable, with no
relation to the one in Log[k+j].

This is not a bug.  Mathematica simply interpreted what you did type,
which is not quite what you intended to do.

Regards.
-- 
  __|__
___\_/___   Paulo Mouat,
   ___      mouat at mail.telepac.pt
  |___|     http://www.geocities.com/Vienna/8804/
  |___|     http://www.trailerpark.com/waltz/mouat/



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