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Re: why no result & no error from this recursion

• To: mathgroup at smc.vnet.net
• Subject: [mg82450] Re: why no result & no error from this recursion
• From: Jon Harrop <jon at ffconsultancy.com>
• Date: Sat, 20 Oct 2007 05:58:57 -0400 (EDT)
• References: <ff9t3q$6bp$1@smc.vnet.net>

Murray Eisenberg wrote:
> Why does the following recursion produce neither a result nor an error
> message -- nor a system crash?
> 
> Block[{$RecursionLimit=50002}, (If[#<1, "", "." <> #0[# - 1]] &)[50000]]
> 
> I even tried setting $RecursionLimit=Infinity, but no change.
> 
> I presume this is just bumping up against a hardware/OS limit, so I'm
> surprised to get no error message and no crash.

Have you tried running this from the command line?

$ MathKernel
Mathematica 5.1 for Linux x86 (64 bit)
Copyright 1988-2004 Wolfram Research, Inc.
 -- Motif graphics initialized --

In[1]:= Block[{$RecursionLimit=50002}, (If[#<1, "", "." <> #0[# - 1]] &
[50000]]
Segmentation fault

-- 
Dr Jon D Harrop, Flying Frog Consultancy
http://www.ffconsultancy.com/products/?u

• Follow-Ups:
  • Re: Re: why no result & no error from this recursion
    • From: Murray Eisenberg <murray@math.umass.edu>