(motive : Option (Lean.FVarId × Subarray Lean.FVarId) → Sort u_1) →
  (x : Option (Lean.FVarId × Subarray Lean.FVarId)) →
    (Unit → motive none) → ((fNew : Lean.FVarId) → (s' : Subarray Lean.FVarId) → motive (some (fNew, s'))) → motive x