{A : Sequence} (a : A 0) k : A k. Proof. induction k as [ | k q]. - exact a. - exact q^+. Defined.
Require Import Basics. Require Import Types. Require Import Diagrams.Diagram. Require Import Diagrams.Sequence. Require Import Diagrams.Cocone. Require Import Colimits.Colimit. Require Import Spaces.Nat.Core. Require Import Homotopy.IdentitySystems.