English
Taking inverses commutes with piecewise: the piecewise of f1^{-1} and g1^{-1} equals the inverse of the piecewise f1 g1.
Русский
Степень инверсий совместима с разбиением на куски: piecewise f1^{-1} g1^{-1} = (piecewise f1 g1)^{-1}.
LaTeX
$$$s.piecewise f_1^{-1} g_1^{-1} = (s.piecewise f_1 g_1)^{-1}$$$
Lean4
@[to_additive]
theorem piecewise_inv [∀ i, Inv (f i)] (s : Set I) [∀ i, Decidable (i ∈ s)] (f₁ g₁ : ∀ i, f i) :
s.piecewise f₁⁻¹ g₁⁻¹ = (s.piecewise f₁ g₁)⁻¹ :=
s.piecewise_op f₁ g₁ fun _ x => x⁻¹