Absolute factorization over QQ(t)

[anonymous]

Absolute factorization fails to factor x2 - t over QQ(t).

                     SINGULAR                                 /  Development
 A Computer Algebra System for Polynomial Computations       /   version 4.1.0
                                                           0<
 by: W. Decker, G.-M. Greuel, G. Pfister, H. Schoenemann     \   Nov 2016
FB Mathematik der Universitaet, D-67653 Kaiserslautern        \
// ** executing /scratch/hannes/snork/Singular/LIB/.singularrc
> LIB "absfact.lib";
// ** loaded /scratch/hannes/snork/Singular/LIB/absfact.lib (4.0.0.0,Jun_2013)
>  ring R = (0, t), (x), dp;
>  poly f = x^2 - t;
>  def S = absFactorize(f);

// 'absFactorize' created a ring, in which a list absolute_factors (the
// absolute factors) is stored.
// To access the list of absolute factors, type (if the name S was assigned
// to the return value):
//        setring(S); absolute_factors;
  
> setring(S);
> absolute_factors;
[1]:
   _[1]=1
   _[2]=x2+(-t)
[2]:
   1,1
[3]:
   _[1]=(a)
   _[2]=(a)
[4]:
   1

[hannes]

will produce an error: only implemented for rational coefficients