BundleRanks -- get the ranks of the tautological sheaves on a flag bundle

i1 : G = projectiveSpace 7

o1 = G

o1 : a flag bundle with ranks {1, 7}

i2 : G.BundleRanks

o2 = {1, 7}

o2 : List

i3 : X = flagBundle {1,2,3}

o3 = X

o3 : a flag bundle with ranks {1, 2, 3}

i4 : X.BundleRanks

o4 = {1, 2, 3}

o4 : List