{motive_1 : Lean.Elab.Tactic.RCases.RCasesPatt → Sort u} →
  (t : Lean.Elab.Tactic.RCases.RCasesPatt) →
    t.ctorIdx = 1 →
      ((ref : Lean.Syntax) → (a : Lean.Name) → motive_1 (Lean.Elab.Tactic.RCases.RCasesPatt.one ref a)) → motive_1 t