Assuming/Block doesn't invoke $Post ?
- To: mathgroup at smc.vnet.net
- Subject: [mg45522] Assuming/Block doesn't invoke $Post ?
- From: "Drago Ganic" <drago.ganic at in2.hr>
- Date: Mon, 12 Jan 2004 02:15:33 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
I thought that I could use something like this to assert that all variables
are real and not complex:
{$Post , $Assumptions} = {Refine, _Symbol \[Element] Reals};
It seems to work with:
Sqrt[x^2]]
Abs[x]
and
Refine[Sqrt[x^2], x > 0]
x
But I would like not to use Refine to make additional assumptions. Instead I
would like to use Assuming:
Assuming[x > 0, Sqrt[x^2]]
Abs[x]
Why doesn't Assuming (or the Block equivalent) apply Refine automatically
?!?!
Greetings from Croatia,
drago