English
If f and g are AEMeasurable, then x ↦ f(x) ⊔ g(x) is AEMeasurable.
Русский
Если f и g AEMeasurable, то x ↦ f(x) ⊔ g(x) измеримо практически.
LaTeX
$$$AEMeasurable f \mu \Rightarrow AEMeasurable g \mu \Rightarrow AEMeasurable\bigl(x \mapsto f(x) \sqcup g(x)\bigr) \mu$$$
Lean4
@[measurability]
theorem sup (hf : AEMeasurable f μ) (hg : AEMeasurable g μ) : AEMeasurable (fun a => f a ⊔ g a) μ :=
measurable_sup.comp_aemeasurable (hf.prodMk hg)