∀ {α β γ : Type w} {m : Type w → Type w'} {n : Type w → Type w''} {lift : ⦃α : Type w⦄ → m α → n α}
  {f : β → Std.Iterators.PostconditionT n (Option γ)} {inner inner_1 : Std.IterM m β},
  { inner := inner } = { inner := inner_1 } → inner = inner_1