{motive_1 : Lean.Elab.Tactic.RCases.RCasesPatt → Sort u} →
  (t : Lean.Elab.Tactic.RCases.RCasesPatt) →
    t.ctorIdx = 5 →
      ((ref : Lean.Syntax) →
          (a : List Lean.Elab.Tactic.RCases.RCasesPatt) → motive_1 (Lean.Elab.Tactic.RCases.RCasesPatt.tuple ref a)) →
        motive_1 t