A : Join A Empty <~> A. Proof. snrapply equiv_adjointify. - apply join_rec; snrapply (Build_JoinRecData idmap); contradiction. - exact joinl. - reflexivity. - snrapply Join_ind; [reflexivity| |]; contradiction. Defined.
Require Import Basics Types. Require Import Cubical.DPath Cubical.PathSquare. Require Import NullHomotopy. Require Import Extensions. Require Import Colimits.Pushout. Require Import Truncations.Core Truncations.Connectedness. Require Import Pointed.Core. Require Import WildCat. Require Import Spaces.Nat.Core.