Note that S is of measure zero if for every ϵ>0 there exist a sequence of open rectangles {Rj} such that \[S \subset \bigcup_{j=1}^\infty R_j \qquad \text{and} \qquad \sum_{j...Note that S is of measure zero if for every ϵ>0 there exist a sequence of open rectangles {Rj} such that S⊂∞⋃j=1Rjand∞∑j=1V(Rj)<ϵ. Furthermore, if S is measure zero and S′⊂S, then S′ is of measure zero.
