English
For any group G and set s ⊆ G, the closure commutes with inversion: closure(s)⁻¹ = closure(s⁻¹).
Русский
Для группы G и множества s ⊆ G замыкание пропускает инверсию: closure(s)⁻¹ = closure(s⁻¹).
LaTeX
$$closure(s)^{-1} = closure(s^{-1})$$
Lean4
@[to_additive]
theorem closure_inv (s : Set G) : closure s⁻¹ = (closure s)⁻¹ :=
by
apply le_antisymm
· rw [closure_le, coe_inv, ← Set.inv_subset, inv_inv]
exact subset_closure
· rw [inv_le, closure_le, coe_inv, ← Set.inv_subset]
exact subset_closure