RE: [Axiom-developer] interesting free algebra text

[Page, Bill]

On Tuesday, December 06, 2005 1:37 PM Tim Daly (root) wrote:
> 
> http://www.johnwoodwark.com/inge/docs/icg.pdf
> 
> for those who want to carve out an interesting algebra area
> (similar to cliff's units work). most interesting is the whole
> question of intervals.
> 

Axiom already contains a significant amount of algebra for
dealing with intervals. See:

http://wiki.axiom-developer.org/axiom--test--1/src/algebra/IntervalSpad

+++ Author: Mike Dewar
+++ Date Created: November 1996
+++ Description:
+++ This category implements of interval arithmetic and transcendental
+++ functions over intervals.

-------

I know that this domain is critical for some of Axiom's integration
algorithms. I am sure that there are some important extensions that
could be made to here.

> ideally we should be able to define functions with the proviso that
> it is only defined over a given interval, as in:
>
>    sin(x) suchthat x in [0.3..0.4]
> ...

I am not convinced that the concept of a proviso is directly
relevant to intervals. It seems too general to me.

Regards,
Bill Page.