diff --git a/Mathlib/MeasureTheory/MeasurableSpace/MeasurablyGenerated.lean b/Mathlib/MeasureTheory/MeasurableSpace/MeasurablyGenerated.lean index 8421c40c186d3f..5c6f705086b839 100644 --- a/Mathlib/MeasureTheory/MeasurableSpace/MeasurablyGenerated.lean +++ b/Mathlib/MeasureTheory/MeasurableSpace/MeasurablyGenerated.lean @@ -42,6 +42,12 @@ lemma generateFrom_singleton_le {m : MeasurableSpace α} {s : Set α} (hs : Meas MeasurableSpace.generateFrom {s} ≤ m := generateFrom_le (fun _ ht ↦ mem_singleton_iff.1 ht ▸ hs) +lemma comap_indicator_const_le_generateFrom_singleton {M : Type*} [Zero M] [MeasurableSpace M] + (s : Set α) (c : M) : + MeasurableSpace.comap (s.indicator (fun _ ↦ c)) inferInstance ≤ + MeasurableSpace.generateFrom {s} := + (measurable_const.indicator (measurableSet_generateFrom (by simp))).comap_le + end MeasurableSpace namespace MeasureTheory