[Axiom-mail] Formal polynomials?

[Alasdair McAndrew]

A quickie:  is there any way of defining a formal polynomial with unknown coefficients, such as:

a_0+a_1*x+a_2*x^2+a_3*x^3  ?

I want to calculate the values of the coefficients by a system of linear equations based on integrations whose integrands include that polynomial.

For small polynomials I can write

p:=a+b*x+c*x^2+d*x^3

but this gets clumsy for higher powers.

I can enter, for example

A:=[a[n] for n in 0..10]

for a list of symbols, but neither of

sum(a[i]*x^i, i=0..10)

or

sum(A.i*x^(i-1),i=1..11)

work, nor do they work when "sum" is replaced with "summation".  

--