(motive : Lean.Meta.Grind.SplitCandidate✝ → Sort u_1) →
  (c? : Lean.Meta.Grind.SplitCandidate✝¹) →
    (Unit → motive Lean.Meta.Grind.SplitCandidate.none✝) →
      ((c' : Lean.Meta.Grind.SplitInfo) →
          (numCases' : ℕ) →
            (isRec tryPostpone' : Bool) →
              motive (Lean.Meta.Grind.SplitCandidate.some✝ c' numCases' isRec tryPostpone')) →
        motive c?