∀ {α : Type u_1} [inst : MeasurableSpace α] {μ : MeasureTheory.Measure α} [inst_1 : TopologicalSpace α]
  [μ.InnerRegularCompactLTTop] [MeasureTheory.IsLocallyFiniteMeasure μ] [R1Space α] [BorelSpace α] {K : Set α},
  IsCompact K → μ K = ⨅ U, ⨅ (_ : K ⊆ U), ⨅ (_ : IsOpen U), μ U