English
For a Set s and a function f: α → G with G a Group, mulIndicator s (f)⁻¹ equals (mulIndicator s f)⁻¹. This is a restatement via the inverse property.
Русский
Для множества s и функции f: α → G, индикатор на f⁻¹ равен инверсии индикатора на f.
LaTeX
$$$$ \\forall s:\\ Set\\,\\alpha, f:\\alpha \\to G,\\ mulIndicator s (f)^{-1} = (mulIndicator s f)^{-1} $$$$
Lean4
@[to_additive]
theorem mulIndicator_inv (s : Set α) (f : α → G) :
(mulIndicator s fun a => (f a)⁻¹) = fun a => (mulIndicator s f a)⁻¹ :=
mulIndicator_inv' s f