Then ∀j ∈ U , we have W i,j i max ≥ W i,j , ∀i > m 1 . The lemma 1 can be proved by contradiction: Assume there ∃i > m 1 , s.t W i,j > W i,j i max for any j ∈ U . If profile j i max is selected to be in Ω(i + 1), then j must also be in Ω(i + 1), which contradicts to the definition of U . If profile j i max is not selected to be in Ω(i + 1), then none of the profiles in P/U can be in Ω(i + 1). In this case, all profiles in Ω(i + 1) are from U , which also contradicts to the definition of U . Hence lemma 1 is proved.To further prove P1, we focus on the difference between local statistics W i,j i max − W i,j for ∀j ∈ U , where the increment value depends on ξ * m,j i max u min and ξ * m,j u min (we consider the positive CUSUM without loss of generality). Thus, it suffices to investigate (Nabhan et al., 2021Note both ξ * m,j and ξ * m,j i max asymptotically follow N (0, 1), thus their expectations are both 0. However, the term ξ * m,j i max − ξ * m,j are not necessarily identical in terms of m. This is because there might be some ms that ξ * m,j i max are jointly sampled with ξ * m,j (unobservable for the j i max ) while some that ξ * m,j i max are sampled independent with ξ * m,j (observable for j i max ). Nevertheless, ξ * m,j i max − ξ * m,j are still independent