Hi GiNaC!

I love the library! Keep up the good work!

Currently I am trying to find exact eigenvalues. My solution so far is to factor the characteristic equation then I can try to find roots of the factored polynomials. But, I need a list of expressions that store the factored polynomials. 

For example in the ginsh I have:

```

> rat = pow(x,6)+1;
1+x^6
> factor(rat);
(1+x^4-x^2)*(1+x^2)

```

Then I need a list with the expressions (1+x^4-x^2) and (1+x^2); from there I can calculate the roots exactly.

Is this possible? Is there a better way to find exact eigenvalues?

Thanks!

Charles