{α β : Type u_1} →
  [inst : Std.Iterator α Id β] →
    [Std.Iterators.Productive α Id] →
      (motive : Std.Iter β → Sort x) →
        ((it : Std.Iter β) →
            ({it' : Std.Iter β} → it.IsPlausibleStep (Std.IterStep.skip it') → motive it') → motive it) →
          (it : Std.Iter β) → motive it