Function: algcharpoly
Section: algebras
C-Name: algcharpoly
Prototype: GGDn
Help: algcharpoly(al,b,{v='x}): (reduced) characteristic polynomial of b in
 \var{al}, with respect to the variable $v$.

Doc: Given an element $b$ in \var{al}, returns its characteristic polynomial
 as a polynomial in the variable $v$. If \var{al} is a table algebra output
 by \tet{algtableinit}, returns the absolute characteristic polynomial of
 \var{b}, which is an element of $\F_p[v]$ or~$\Q[v]$; if \var{al} is a
 central simple algebra output by \tet{alginit}, returns the reduced
 characteristic polynomial of \var{b}, which is an element of $K[v]$ where~$K$
 is the center of \var{al}.
 \bprog
 ? al = alginit(nfinit(y), [-1,-1]); \\ (-1,-1)_Q
 ? algcharpoly(al, [0,1]~)
 %2 = x^2 + 1
 @eprog

 Also accepts a square matrix with coefficients in \var{al}.