English
If f has compact multiplicative support, then its inverse f^{-1} also has compact multiplicative support.
Русский
Если mulTSupport(f) компактна, то и mulTSupport(f^{-1}) компактна.
LaTeX
$$$\\text{HasCompactMulSupport}(f) \\Rightarrow \\text{HasCompactMulSupport}(f^{-1}).$$$
Lean4
@[to_additive]
protected theorem inv {α β : Type*} [TopologicalSpace α] [DivisionMonoid β] {f : α → β} (hf : HasCompactMulSupport f) :
HasCompactMulSupport (f⁻¹) := by simpa only [HasCompactMulSupport, mulTSupport, mulSupport_inv] using hf