∀ {α : Type u_1} (motive : Option (Stream'.Seq1 α) → Sort u_2) (a : α) (s' : Stream'.Seq α) (h_1 : Unit → motive none)
  (h_2 : (a : α) → (s' : Stream'.Seq α) → motive (some (a, s'))),
  (match some (a, s') with
    | none => h_1 ()
    | some (a, s') => h_2 a s') =
    h_2 a s'