Oh agreed, (I was assuming I could easily use eg 20 unpadded bits or whatnot for unique_library_size # but not necessarily get away with it easily for library_s

Oh agreed, (I was assuming I could easily use eg 20 unpadded bits or whatnot for unique_library_size # but not necessarily get away with it easily for library_size; when that's the case it's always true that unique_library_size # needs less storage than library_size). Edit: to correct...it's always true that unique_libary_size # needs less storage than library_size except under very unlikely circumstances (...circumstances which get ruled out anyways if you do a more-granular calculation for when this strategy would make sense to consider).