`{Funext} C : @path_precategory_uncurried' _ C C (idpath; (idpath; (idpath, idpath))) = idpath. Proof. destruct C; cbn in *. rewrite !(contr idpath). reflexivity. Qed.
Require Import Category.Core. Require Import HoTT.Basics.Equivalences HoTT.Basics.PathGroupoids HoTT.Basics.Trunc HoTT.Basics.Tactics. Require Import HoTT.Types.Sigma HoTT.Types.Arrow HoTT.Types.Forall. Require Import HoTT.Tactics.