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From: Peter Freyd <pjf@saul.cis.upenn.edu>
To: categories@mta.ca
Cc: mm.mawanda@nul.ls
Subject: Re: stupid question?
Date: Wed, 29 Mar 2000 15:23:16 -0500 (EST)	[thread overview]
Message-ID: <200003292023.PAA12854@saul.cis.upenn.edu> (raw)

 M.M. Mawanda asks:

>I have been asked the following question: Is it true that any function
>defined in a real number closed interval [a,b] (there is not a hypothesis
>of continuity) is bounded in an open  subinterval (c,d) of [a,b]? My
>spontaneous was NO. Unfortunately I cannot find a counter-example to
>disapproved my answer. Can someone help.     

No it is not true. For example, the function defined by:

  f(x) =  if  x  is irrational then  0  else
          if  x =  p/q  where  p  and  q  are co-prime then  q.



             reply	other threads:[~2000-03-29 20:23 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2000-03-29 20:23 Peter Freyd [this message]
2000-03-30  1:32 ` question? Michael Barr
  -- strict thread matches above, loose matches on Subject: below --
2000-03-29 23:13 Re: stupid question? Max Kanovitch
2000-03-30  3:00 ` Todd Wilson
2000-03-29 21:48 Wendt, Michael - SSMD/DMES
2000-03-29 17:36 M.M. Mawanda

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