Function: algbasis
Section: algebras
C-Name: algbasis
Prototype: mG
Help: algbasis(al): basis of the stored order of the central simple algebra al.
Doc: Given a central simple algebra \var{al} output by \tet{alginit}, returns
 a $\Z$-basis of the order~${\cal O}_0$ stored in \var{al} with respect to the
 natural order in \var{al}. It is a maximal order if one has been computed.
 \bprog
 A = alginit(nfinit(y), [-1,-1]);
 ? algbasis(A)
 %2 =
 [1 0 0 1/2]

 [0 1 0 1/2]

 [0 0 1 1/2]

 [0 0 0 1/2]
 @eprog
