English
If g is a uniformly continuous continuous map, then precomposition by g induces a uniformly continuous map on function spaces: f ↦ f ∘ g.
Русский
Если g непрерывно сверху по униформности и равномерна, то предваривающее композицию по g образует равномерно непрерывную карту на пространства функций: f ↦ f ∘ g.
LaTeX
$$$g:\, C(β, δ)$, $hg:\, UniformContinuous\ g \Rightarrow\ UniformContinuous\ (f\mapsto g\circ f)$$$
Lean4
theorem uniformContinuous_comp (g : C(β, δ)) (hg : UniformContinuous g) :
UniformContinuous (ContinuousMap.comp g : C(α, β) → C(α, δ)) :=
isUniformEmbedding_toUniformOnFunIsCompact.uniformContinuous_iff.mpr <|
UniformOnFun.postcomp_uniformContinuous hg |>.comp isUniformEmbedding_toUniformOnFunIsCompact.uniformContinuous