Example from Schubert: Hilbert polynomial and Todd class of projective 3-space

> proj(3,h,all): factor(chi(o(n*h)));
                          1/6 (n + 3) (n + 2) (n + 1)

i1 : Ph = abstractProjectiveSpace'_3 base n

o1 = Ph

o1 : a flag bundle with subquotient ranks {3, 1}

i2 : factor chi OO(n*h)

                           1
o2 = (n + 1)(n + 2)(n + 3)(-)
                           6

o2 : Expression of class Product

> Ph[toddclass_];
                                           2  2    3  3
                         1 + 2 h t + 11/6 h  t  + h  t

i3 : todd Ph

              11 2    3
o3 = 1 + 2h + --h  + h
               6

                     QQ[n][H   ..H   , h]
                            1,1   1,3
o3 : ----------------------------------------------------
     (- H    - h, - H    - H   h, - H    - H   h, -H   h)
         1,1         1,2    1,1      1,3    1,2     1,3