Abuur nooc ka mid ah weedhan oo ka sii dhib badan Topolojiyada heerarka badan, isku xirnaanta heerka sare ee isku xirnaanta heerka hoose sida ku cad jaantuska 1.
Dabcan, nooc ka mid ah jumlada ka adag waa "In topologies multistage, heerka sare wareejinta qanjidhada xirmaan heerka hoose wareejinta qanjidhada sida ku cad jaantuska 1, halkaas oo wareejinta qanjidhada ee darajo 0 si toos ah u xirmaan qanjidhada processor halka wareejinta qanjidhada ee darajo 1 xirmaan qanjidhada wareejinta ee darajo 0. "