For non-negative measurable f_n: ∫ liminf f_n ≤ liminf ∫ f_n. Converts pointwise liminfs to measure-liminfs; used widely to construct integrable limits.
For non-negative measurable f_n: ∫ liminf f_n ≤ liminf ∫ f_n. Converts pointwise liminfs to measure-liminfs; used widely to construct integrable limits.