Measure, Integration & Real Analysis · Problem 2C.5
Measures — Sheldon Axler
Mathematics — Measure Theory · measures
Problem
Suppose (X,S,μ) is a measure space such that μ(X)<∞. Prove that if A is a set of disjoint sets in S such that μ(A)>0 for every A∈A, then A is a countable set.