{motive : Lean.Elab.Tactic.Do.SuccessPoint✝ → Sort u} →
  (t : Lean.Elab.Tactic.Do.SuccessPoint✝¹) →
    ((lvl : Lean.Level) →
        (cursorPred letMutsPred : Lean.Expr) →
          motive { lvl := lvl, cursorPred := cursorPred, letMutsPred := letMutsPred }) →
      motive t