`(@IsIsomorphism C y z p) `(@IsIsomorphism C x z q) : (p^-1 o q)^-1 = q^-1 o p. Proof. iso_concat_t. Qed.
Require Import Category.Core Functor.Core. Require Import HoTT.Tactics Basics.Trunc Basics.Tactics Types.Sigma Equivalences.