English
The connected component of 1_G in a topological group G forms a subgroup of G.
Русский
Связанная компонента единицы 1_G в топологической группе G образует подгруппу G.
LaTeX
$$$\operatorname{connectedComponentOfOne}(G) \le G$$$
Lean4
@[to_additive]
theorem inv_mem_connectedComponent_one {G : Type*} [TopologicalSpace G] [DivisionMonoid G] [ContinuousInv G] {g : G}
(hg : g ∈ connectedComponent (1 : G)) : g⁻¹ ∈ connectedComponent (1 : G) :=
by
rw [← inv_one]
exact Continuous.image_connectedComponent_subset continuous_inv _ ((Set.mem_image _ _ _).mp ⟨g, hg, rfl⟩)