Definition 0.1. A regular measure μR on a topological space X is a measure on X such
that for each A ∈ℬ(X) , with μR(A) < ∞), and each 𝜀 > 0 there exist a compact subset K
of X and an open subset G of X with K ⊂ A ⊂ G, such that for all sets A′∈ℬ(X) with
A′⊂ G − K, one has μR(A′) < 𝜀.
