New in version 2.0.
Inventory aggregate subsets:
abjad> U_star = pitchtools.inventory_aggregate_subsets()
abjad> len(U_star)
4096
abjad> for pcset in U_star[:20]:
... pcset
NumberedChromaticPitchClassSet([])
NumberedChromaticPitchClassSet([0])
NumberedChromaticPitchClassSet([1])
NumberedChromaticPitchClassSet([0, 1])
NumberedChromaticPitchClassSet([2])
NumberedChromaticPitchClassSet([0, 2])
NumberedChromaticPitchClassSet([1, 2])
NumberedChromaticPitchClassSet([0, 1, 2])
NumberedChromaticPitchClassSet([3])
NumberedChromaticPitchClassSet([0, 3])
NumberedChromaticPitchClassSet([1, 3])
NumberedChromaticPitchClassSet([0, 1, 3])
NumberedChromaticPitchClassSet([2, 3])
NumberedChromaticPitchClassSet([0, 2, 3])
NumberedChromaticPitchClassSet([1, 2, 3])
NumberedChromaticPitchClassSet([0, 1, 2, 3])
NumberedChromaticPitchClassSet([4])
NumberedChromaticPitchClassSet([0, 4])
NumberedChromaticPitchClassSet([1, 4])
NumberedChromaticPitchClassSet([0, 1, 4])
There are 4096 subsets of the aggregate.
This is U* in [Morris 1987].
Return list of numbered chromatic pitch-class sets.