... www.MATHVN.com - Anh Quang Le, PhDwww.MathVn.com - Math VietnamMEASURE and INTEGRATION Problems with Solutions Anh Quang Le, Ph.D.October 8, 201319Problem 13Let µ∗be an outer measure on ... (En)n∈Nin A such thatlimn→∞En= ∅ with limn→∞µ(En) = 0.SolutionSince X is a infinite set, we can find an countably infinite set {x1, x2, } ⊂ X with xi= xjif i = j. Let En= ... measurable.(ii) For every ε > 0, there exists an open set O ⊃ E with µ∗L(O \ E) ≤ ε .(iii) There exists a Gδ-set G ⊃ E with µ∗L(G \E) = 0.Solution• (i) ⇒ (ii) Suppose that E is measurable....