proposition: Theorem _paco6_fold: forall r, gf (upaco6 gf r) <6== paco6 gf r.
proof: Proof. intros. apply uncurry_adjoint1_6. eapply le1_trans; [| apply _paco_fold]. apply le1_refl. Qed.
imports: Program.Basics Paco(paconotation_internal paco_internal pacotac_internal)