F.BundleRanks
i1 : G = abstractProjectiveSpace 7 o1 = G o1 : a flag bundle with subquotient ranks {1, 7}
i2 : G.BundleRanks o2 = {1, 7} o2 : List
i3 : X = flagBundle {1,2,3} o3 = X o3 : a flag bundle with subquotient ranks {1..3}
i4 : X.BundleRanks o4 = {1, 2, 3} o4 : List
The object BundleRanks is a symbol.