Function: idealnumden
Section: number_fields
C-Name: idealnumden
Prototype: GG
Help: idealnumden(nf,x): returns [A,B], where A,B are coprime integer ideals
 such that x = A/B.
Doc: returns $[A,B]$, where $A,B$ are coprime integer ideals
 such that $x = A/B$, in the number field $\var{nf}$.
 \bprog
 ? nf = nfinit(x^2+1);
 ? idealnumden(nf, (x+1)/2)
 %2 = [[1, 0; 0, 1], [2, 1; 0, 1]]
 @eprog
