∀ {motive_1 : Lean.MessageData → Sort u} {motive_2 : Array Lean.MessageData → Sort u}
  {motive_3 : List Lean.MessageData → Sort u} (t : Lean.MessageData)
  (F_1 : (t : Lean.MessageData) → t.below → motive_1 t)
  (F_2 : (t : Array Lean.MessageData) → Lean.MessageData.below_1 t → motive_2 t)
  (F_3 : (t : List Lean.MessageData) → Lean.MessageData.below_2 t → motive_3 t),
  t.brecOn F_1 F_2 F_3 = F_1 t (Lean.MessageData.brecOn.go t F_1 F_2 F_3).2