∀ {ι : Type u_1} {α : Type u_2} {β : Type u_3} [inst : Semifield α] [inst_1 : LinearOrder α] [IsStrictOrderedRing α]
  [inst_3 : Semifield β] [inst_4 : LinearOrder β] [IsStrictOrderedRing β] {s : Set ι} {f : ι → α} {g : ι → β},
  (∀ i ∈ s, 0 < f i) → (∀ i ∈ s, 0 < g i) → AntivaryOn f g s → AntivaryOn f⁻¹ g⁻¹ s