∀ {α : Type u_3} {β : Type u_4} [inst : AddCommGroup β] [IsAddTorsionFree β] [inst_2 : InvolutiveNeg α] {f : α → β},
  Function.Odd f → ∀ {s : Finset α}, Finset.map (Equiv.toEmbedding (Equiv.neg α)) s = s → s.sum f = 0