(motive : Option (Lean.Diff.Action × String) → Sort u_1) →
  (x : Option (Lean.Diff.Action × String)) →
    ((a₂ : Lean.Diff.Action) → (s₂ : String) → motive (some (a₂, s₂))) →
      ((x : Option (Lean.Diff.Action × String)) → motive x) → motive x