Robert Dodier wrote:
> On Mon, Mar 3, 2008 at 8:36 AM, Stavros Macrakis <macrakis at alum.mit.edu> wrote:
>
>> I must be missing something here. Why is derivace sometimes linear
>> and sometimes not?
>
> Well, I think the goal is to reimplement the rules for derivatives,
> but under control of the user, so that only one rule is applied
> at a time.
>
> A rule for linearity could also be constructed via defrule,
> in which case the declare(..., linear) and remove(..., linear)
> stuff isn't needed.
>
defrule is in fact better, since this covers cases like
derivace(x^2*a^2) which are not covered by declare(..., linear)
I use the following code for constant multiple rule:
freeofx (e) := freeof ('x, e);
notfreeofx (e) := not freeof ('x, e);
freeofx_not1 (e) := e # 1 and freeofx (e);
matchdeclare(a,notfreeofx,k,freeofx_not1);
defrule(c2, derivace(k*a), k*derivace(a));
The site with these calculations is (English is not yet available and I
continue to improve the code) on
http://user.mendelu.cz/marik/maw/index.php?lang=en&form=derivace
I hope, this will be useful for students.
Thank you again for all hints I got from this maillist.
Robert Marik
> Robert
>