∀ {m : Type u → Type v} {ps : Std.Do.PostShape} {α : Type u} {Q : Std.Do.PostCond (Option α) ps} [inst : Std.Do.WP m ps]
  (x : OptionT m α), ⦃(Std.Do.wp x).apply (fun a => Q.1 (some a), fun x => Q.1 none, Q.2)⦄ x.run ⦃Q⦄