Canonical Structure YLpsi_tau : Map0'' (F a) (NT_setoid (FunSET a) F) :=
   YLpsi_arrow_map_law.

(* Specifications: *)
Lemma YonedaLemma : forall (a : C) (F : Functor C SET), AreBij0'' (YLpsi_tau a F) (YLphi_tau a F).