proposition: Lemma unique_helper c : (a * b) c = F c.
proof: Proof. pose proof (ap (fun F => object_of F c) H1). pose proof (ap (fun F => object_of F c) H2). simpl in *. path_induction. apply eta_prod. Defined.
imports: Category.Core Functor.Core Category.Prod Functor.Composition.Core Functor.Prod.Core Functor.Paths Types.Prod HoTT.Tactics Types.Forall Types.Sigma Basics.Tactics