{motive : Turing.ToPartrec.Cont → Sort u} →
  (t : Turing.ToPartrec.Cont) →
    t.ctorIdx = 1 →
      ((a : Turing.ToPartrec.Code) →
          (a_1 : List ℕ) → (a_2 : Turing.ToPartrec.Cont) → motive (Turing.ToPartrec.Cont.cons₁ a a_1 a_2)) →
        motive t