Function: algdim
Section: algebras
C-Name: algdim
Prototype: lGD0,L,
Help: algdim(al,{abs=0}): dimension of the algebra al.
Doc: If \var{al} is a table algebra output by \tet{algtableinit} or if~$abs=1$,
 returns the dimension of \var{al} over its prime subfield ($\Q$ or $\F_p$).
 If~\var{al} is a central simple algebra output by \tet{alginit} and~$abs=0$,
 returns the dimension of \var{al} over its center.

 \bprog
 ? nf = nfinit(y^3-y+1);
 ? A = alginit(nf, [-1,-1]);
 ? algdim(A)
 %3 = 4
 ? algdim(A,1)
 %4 = 12
 @eprog
