Re: [Axiom-developer] groebner?

[Martin Rubey]

"Raymond E. Rogers" <address@hidden> writes:

> Could someone tell me if this is wrong; or if it's right why?

It's wrong, I guess.
 
> list:=[p,Vr,Vt,e]
> eq1H:=((-Vr^3+Vr^2)*Vt+Vr^3-Vr^2)*p :: HDMP(list,POLY INT)

                                                   ^^^^^^^^
                                                   ||||||||

you are saying that the coefficients of your polynomial are polynomials. That's
probably confusing. 
 
> (24) -> eq1H
>                3     2        3     2
>    (24)  ((- Vr  + Vr )Vt + Vr  - Vr )p

>From this output you can deduce that ((-Vr^3+Vr^2)*Vt+Vr^3-Vr^2) is interpreted
as coefficient and p as variable...

Thus the output of

> (25) -> groebner [eq1H]
> (25) ->
>    (25)  [p]

Is correct, in some sense. Although I agree that it is confusing. Try

eq1H := (((-Vr^3+Vr^2)*Vt+Vr^3-Vr^2)*p) :: HDMP(list,INT)

instead. You need the parentheses, because otherwise Axiom will coerce only p
to a HDMP, and eq1H will be of type POLY INT

Martin