Ithiyori Ngokuvamile, ukuhlaziywa kosayizi wezinhlayiyana kunikeza izilinganiso zezinhlamvu zamadayamitha ahlukene; lokhu kuhlaziya kungenziwa ngokusefa noma ngokufakwa kwenhlabathi emanzini ngokusetshenziswa komthetho kaStokes.
Ngokuya ngosayizi kanye nenani lezinhlamvu ezakha i-aggregate, ama-aggregate abizwa ngokuthi izinhlawulo, izihlabathi, amatshe noma amatshe. Kodwa-ke, ngenani elinikeziwe, zonke izinhlamvu ezihlanganisayo azinawo wonke usayizi ofanayo.
Ukuze wenze lokhu, okusanhlamvu kuhlukaniswa ochungechungeni lwama-sieve akhiwe.