English
Let f: G →* Hˣ be a monoid hom. If the composite (Units.coeHom H) ∘ f is continuous, then f is continuous.
Русский
Пусть f: G →* Hˣ — моноидная гомоморфия. Если композиция (Units.coeHom H) ∘ f непрерывна, тогда f непрерывна.
LaTeX
$$$ \\text{Continuous}(((Units.coeHom H) \\circ f)) \\Rightarrow \\text{Continuous}(f) $$$
Lean4
theorem of_coeHom_comp [Group G] [Monoid H] [TopologicalSpace G] [TopologicalSpace H] [ContinuousInv G] {f : G →* Hˣ}
(hf : Continuous ((Units.coeHom H).comp f)) : Continuous f :=
by
apply continuous_induced_rng.mpr ?_
refine continuous_prodMk.mpr ⟨hf, ?_⟩
simp_rw [← map_inv]
exact MulOpposite.continuous_op.comp (hf.comp continuous_inv)