Re: mma big bad bug

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Article #980

#980

From: mike hurley
Date: Tue, 05 Jan 1993 16:33

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In article <1993Jan5.145612.11165@Arco.COM>, jrowney@arco.com wrote:
> 
> In article <15326.2b48512a@ohstpy.mps.ohio-state.edu>
> vandesande@ohstpy.mps.ohio-state.edu writes:
> >
> >Here is a bizzarre mma bug.  Try entering:
> >
> >Pi*Sqrt[Pi]/(2*3*Sqrt[2])
> >
> >This is very bad.  If anyone knows what is going on,
> >I would like to hear from them.
> >
> >Brett
> >
> 
> Quite bizarre -- Mathematica just seems to stop dead in its tracks!
> 
> Mac IIfx, MMA 2.102
> 
> John
> jrowney@arco.com

From a look at this with tracing turned on, it seems that Mma is getting
caught in an infinite loop, changing Sqrt[(Pi^3)/8]/3 into (Pi/2)^(3/2)/3
and then back again. I'm speculating that the first change is an attempt
to simplify the total expression and the second is an attempt to make the
output "prettier". Bad news.  (mma 2.0 on a sparc; similar results with
the windows version). 

mike hurley   mgh3@po.cwru.edu
dept of mathematics
case western reserve univ. 44106-7058

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From: mgh3@po.cwru.edu (mike hurley)
Newsgroups: sci.math.symbolic
Subject: Re: mma big bad bug
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Date: 5 Jan 1993 16:33:40 GMT
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