(motive : Option (Array ℕ × Subarray (Array ℕ)) → Sort u_1) →
  (x : Option (Array ℕ × Subarray (Array ℕ))) →
    (Unit → motive none) → ((poss : Array ℕ) → (s' : Subarray (Array ℕ)) → motive (some (poss, s'))) → motive x