{α : Type u_1} →
  (P : Vector α 0 → Prop) →
    (motive : Decidable (P #v[]) → Sort u_2) →
      (x : Decidable (P #v[])) → ((h : P #v[]) → motive (isTrue h)) → ((h : ¬P #v[]) → motive (isFalse h)) → motive x