{R : Type u_1} →
  [inst : Semiring R] →
    {motive : Polynomial.Sequence R → Sort u} →
      (t : Polynomial.Sequence R) →
        ((elems' : ℕ → Polynomial R) →
            (degree_eq' : ∀ (i : ℕ), (elems' i).degree = ↑i) → motive { elems' := elems', degree_eq' := degree_eq' }) →
          motive t