algmultable

Function: algmultable
Section: algebras
C-Name: algmultable
Prototype: mG
Help: algmultable(al): multiplication table of al over its prime subfield.
Doc:
 returns a multiplication table of \var{al} over its
 prime subfield ($\Q$ or $\F_p$), as a \typ{VEC} of \typ{MAT}: the left
 multiplication tables of basis elements. If \var{al} was output by
 \tet{algtableinit}, returns the multiplication table used to define \var{al}.
 If \var{al} was output by \tet{alginit}, returns the multiplication table of
 the order~${\cal O}_0$ stored in \var{al}.
 \bprog
 ? A = alginit(nfinit(y), [-1,-1]);
 ? M = algmultable(A);
 ? #M
 %3 = 4
 ? M[1]  \\ multiplication by e_1 = 1
 %4 =
 [1 0 0 0]

 [0 1 0 0]

 [0 0 1 0]

 [0 0 0 1]

 ? M[2]
 %5 =
 [0 -1  1  0]

 [1  0  1  1]

 [0  0  1  1]

 [0  0 -2 -1]
 @eprog