Function: rnfcharpoly
Section: number_fields
C-Name: rnfcharpoly
Prototype: GGGDn
Help: rnfcharpoly(nf,T,a,{var='x}): characteristic polynomial of a
 over nf, where a belongs to the algebra defined by T over nf. Returns a
 polynomial in variable var (x by default).
Doc: characteristic polynomial of
 $a$ over $\var{nf}$, where $a$ belongs to the algebra defined by $T$ over
 $\var{nf}$, i.e.~$\var{nf}[X]/(T)$. Returns a polynomial in variable $v$
 ($x$ by default).
 \bprog
 ? nf = nfinit(y^2+1);
 ? rnfcharpoly(nf, x^2+y*x+1, x+y)
 %2 = x^2 + Mod(-y, y^2 + 1)*x + 1
 @eprog
