Re: Problem using factorff()

[Igor Schein <igor@txc.com>]

On Mon, Jun 09, 2003 at 02:58:39PM +0200, Bodo Schulze wrote:
> Hi all,
> 
> ### Take a simple polynomial
> ? b=x^2
> %11 = x^2
> ### Initalize the field
> ? e=ffinit(2,3)
> %12 = Mod(1, 2)*x^3 + Mod(1, 2)*x + Mod(1, 2)
> ### Try to factor the polynomial
> ? factorff(b,2,e)
>   ***   polynomial variable must be of higher priority than finite field
> variable in factorff.

Here's the correct syntax:

? factorff(x^2,2,ffinit(2,3,y))

[Mod(Mod(1, 2), Mod(1, 2)*y^3 + Mod(1, 2)*y^2 + Mod(1, 2))*b + Mod(Mod(0, 2), Mod(1, 2)*y^3 + Mod(1, 2)*y^2 + Mod(1, 2)) 1]

The polynomial defining a finite field needs to be in y if the
splitting polynomial is in x, since y is of a lower priority.

Igor