Function: algabsdim
Section: algebras
C-Name: algabsdim
Prototype: lG
Help: algabsdim(al): dimension of the algebra al over its prime subfield.
Doc: Given an algebra \var{al} output by \tet{alginit} or by
 \tet{algtableinit}, returns the dimension of \var{al} over its prime subfield
 ($\Q$ or $\F_p$).
 \bprog
 ? nf = nfinit(y^3-y+1);
 ? A = alginit(nf, [-1,-1]);
 ? algabsdim(A)
 %3 = 12
 @eprog
