{α : Type u_1} →
  {motive : Lean.MessageData.VisitStep✝ α → Sort u} →
    (t : Lean.MessageData.VisitStep✝ α) →
      ((butFirst : Option α) → motive (Lean.MessageData.VisitStep.descend✝ butFirst)) →
        ((returning : Option α) → motive (Lean.MessageData.VisitStep.ascend✝ returning)) → motive t