Mma bug
- To: mathgroup at yoda.physics.unc.edu
- Subject: Mma bug
- From: Jack K. Cohen <jkc at dix.mines.colorado.edu>
- Date: Thu, 7 Jan 93 12:36:21 -0700
[Watch for follow up on this issue from WRI. -smc]
The internet is alive with news of a simple expression that
hangs up mma. I am 99.9% sure that someone from wri must
have picked up the bad news, but just to assure that last .1% ...
2
Pi Sqrt[Pi] /(6 Sqrt[2]) //Timing
$IterationLimit::itlim: Iteration limit of 4096 exceeded.
3
Pi
Sqrt[---]
8
{49.8833 Second, Hold[---------]}
3
The apparent problem is an infinite oscillation between writing
Sqrt[8] and writing 2 Sqrt[2]. You can replace 2 by 5, 7, ...
and get the same hang up (eg. 10 Sqrt[5] in the denominator).
More complicated expressions don't fall victim to this deadlock and
undoubtedly that's how this slipped by for so long. I am sure some
programmer at wri feels like crawling under a rock today and he/she
has my sympathy as a fellow hacker.
Jack