a * b = F. Proof. path_functor. exists (path_forall _ _ unique_helper). apply unique_helper2. Defined.
Require Import Category.Core Functor.Core Category.Prod Functor.Composition.Core Functor.Prod.Core. Require Import Functor.Paths. Require Import Types.Prod HoTT.Tactics Types.Forall Types.Sigma. Require Import Basics.Tactics.