यदि `A={2,4,6,8,10}, B = ( 1, 2, 3, 4, 5, 6, 7), C = {2, 6, 7, 10}` और `U = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}` तब सत्यापित कीजिय की
`A uu (B uu C) = ( A uu B ) uu C`