{G : Type u_1} →
  [inst : Add G] →
    {motive : UniqueSums G → Sort u} →
      ((uniqueAdd_of_nonempty : ∀ {A B : Finset G}, A.Nonempty → B.Nonempty → ∃ a0 ∈ A, ∃ b0 ∈ B, UniqueAdd A B a0 b0) →
          motive ⋯) →
        (t : UniqueSums G) → motive t