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Topic: Applying Mathematica to practical problems
Replies: 6   Last Post: Jun 3, 2013 11:13 PM

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 Andrzej Kozlowski Posts: 226 Registered: 1/29/05
Re: Applying Mathematica to practical problems
Posted: Jun 3, 2013 11:13 PM

On 3 Jun 2013, at 17:14, Richard Fateman <fateman@EECS.Berkeley.EDU> wrote:

> On 6/3/2013 8:01 AM, Richard Fateman wrote:
> I said..
> Solve[x+1==x,x] returns {}
> yet
> 1`0 +1`0 == 1`0 returns True.
>
> oops. make that last line 1`0+1 == 1`0 .
>
> Changing the semantics of == to the semantics of === may help
> in some circumstances, but it seems to me we went through this
> before.
> RJF

I forgot to deal with this little thing. Solve solves over the (exact) complex numbers. 1`0 is not an exact real number hence it is not an exact complex number. Non-exact reals and complexes are not included so your "proof" is just a bluff.

Andrzej Kozlowski

PS. I realize that Mathematica gives:

Element[1`0, Reals]

True

I have never liked this and I think it ought to be changed (unless something important depends on this).

Date Subject Author
6/3/13 Andrzej Kozlowski
6/3/13 Andrzej Kozlowski
6/3/13 Richard Fateman
6/3/13 Andrzej Kozlowski