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Re: Numerical accuracy/precision - this is a bug or a feature?

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  • Subject: [mg120321] Re: Numerical accuracy/precision - this is a bug or a feature?
  • From: Murray Eisenberg <murray at math.umass.edu>
  • Date: Tue, 19 Jul 2011 06:54:38 -0400 (EDT)

Mathematica will not allow you to prove that 1 == 0. It says False!

Perhaps you, a human, would wish to deduce something opposite, from 
results that are contrary to other conventions or expectation. But 
still, Mathematica knows what's what here.  And even that 2 + 2 == 7 is 
False.

On 7/18/11 6:13 AM, slawek wrote:
>
> ...Mathematica uses a different convention. By default, assumes that numbers
> such as 1.4 or 2.0 are inaccurate. It is even worse, because though a == b
> is True, then N [a] and N [b] are not the same. Hence we can prove that 1 ==
> 0, or if you prefer that 2 +2 == 7 .
>
> It is a feature, but in my opinion it may leads to serious bugs.
>
> slawek
>
>
>

-- 
Murray Eisenberg                     murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower      phone 413 549-1020 (H)
University of Massachusetts                413 545-2859 (W)
710 North Pleasant Street            fax   413 545-1801
Amherst, MA 01003-9305


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