i1 : X = PP^4
o1 = X
o1 : a flag bundle with subquotient ranks {1, 4}
i2 : X.Base
o2 = point
o2 : an abstract variety of dimension 0
i3 : dim X
o3 = 4
The projective space produced adheres to the older, "Fulton-style" notation, with a tautological subbundle of rank 1. For the opposite, "Grothendieck-style" notation, see PP'.