If a number is given, the ordering is the same as when the module is displayed:
i1 : g=simpleLieAlgebra("A",2);
i2 : (adjointModule g)^**3 2 4 8 2 6 4 2 o2 = (LL (g)) ++ (LL (g)) ++ (LL (g)) ++ (LL (g)) ++ (LL (g)) ++ (LL (g)) ++ LL (g) ++ (LL (g)) 0,0 0,3 1,1 1,4 2,2 3,0 3,3 4,1 o2 : LieAlgebraModule over g
i3 : oo_2 o3 = LL (g) 1,1 o3 : irreducible LieAlgebraModule over g
Instead one can simply use a weight or irreducible module as subscript:
i4 : g=simpleLieAlgebra("A",3);
i5 : M=(adjointModule g)^**2 o5 = M o5 : LieAlgebraModule over g
i6 : describe M 2 o6 = LL (g) ++ LL (g) ++ LL (g) ++ (LL (g)) ++ LL (g) ++ LL (g) 0,0,0 0,1,2 0,2,0 1,0,1 2,0,2 2,1,0
i7 : M_{1,0,1} o7 = 2
i8 : M_(trivialModule g) o8 = 1