Function: algnorm
Section: algebras
C-Name: algnorm
Prototype: GG
Help: algnorm(al,x): (reduced) norm of x.
Doc: Given an element \var{x} in \var{al}, computes its norm. If \var{al} is
 a table algebra output by \tet{algtableinit}, returns the absolute norm of
 \var{x}, which is an element of $\F_p$ of~$\Q$; if \var{al} is a central
 simple algebra output by \tet{alginit}, returns the reduced norm of \var{x},
 which is an element of the center of \var{al}.
 \bprog
 ? mt = [matid(3), [0,0,0; 1,1,0; 0,0,0], [0,0,1; 0,0,0; 1,0,1]];
 ? A = algtableinit(mt,19);
 ? algnorm(A,[0,-2,3]~)
 %3 = 18
 @eprog

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