[Aldor-l] Re: Aldor program: Assistance requested.

[Ralf Hemmecke]

Hi Constantine,

Aldor is an ordinary programming language so there is not really an 
interactive environment (it seems you are looking for that). If you are 
looking for something interactive then you should try Axiom 
http://www.axiom-developer.org.

The Aldor libraries (in particular AlgebraLib) are at the moment quite
weak with respect to manipulation of arbitrary expressions. There is, 
however, a category 'ExpressionType' and several domains starting with 
'ExpressionTree...'. Unfortunately, lots of things are still missing 
there, in particular 'sin' and 'tan'.

However, since Aldor is a typed language, one could also think of not 
using arbitrary expressions (which are somehow typeless). In your case 
you would need a structure (probably a ring or field) that involves 
trigonometric functions and allows differentiation. Then

z3 = simple(...)

would not even be needed since the domain that implements the structure 
has to take care of keeping everying consistent. Only when it comes to 
output a result there should be some options for the user on how s/he 
want the result to show on screen.

I believe my answer doen't help very much, does it?

Ralf


C.Frangos wrote:
> Hi Ralf,
> 
> Thanks for the reply. By symbolic computing I mean manipulating 
> symbols/expressions, symbolic differentiation, simplification, etc. For 
> example,
> 
> x1 = sin(y1);
> x2 = cos(y2);
> z1 = x1^2 + x1*x2 - tan(y2);
> z2 = diff(x1,y1);
> 
> z3 = simple((x1+x2)^2);
> 
> Regards,
> 
> C. Frangos.