The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » Inactive » comp.soft-sys.math.mathematica

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

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

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Andrzej Kozlowski

Posts: 226
Registered: 1/29/05
Re: Applying Mathematica to practical problems
Posted: Jun 3, 2013 11:13 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

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.

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]


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

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.