Powering symbolic polynomial

[Adam Janovský]

Hello,

I'm having difficulties with evaluating polynomial with symbolic coefficients. I'm newbie to Sage and I have no idea how to tackle this.

Let's say, I have polynomial, where coefficients are symbolic. Let's call this polynomial f. I need to perform a function on f, let's say 

function(f):

     return f^4 + f^2 + f + 1 modulo g

where g is irreducible polynomial. Also, The coefficients are modulo q. 

Can anyone guide me please?

[Dima Pasechnik]

I'd convert everything into a setting of polynomial rings; I don't think you can get very far with using symbolic ring here.