--- /dev/null
+(**************************************************************************)
+(* ___ *)
+(* ||M|| *)
+(* ||A|| A project by Andrea Asperti *)
+(* ||T|| *)
+(* ||I|| Developers: *)
+(* ||T|| The HELM team. *)
+(* ||A|| http://helm.cs.unibo.it *)
+(* \ / *)
+(* \ / This file is distributed under the terms of the *)
+(* v GNU General Public License Version 2 *)
+(* *)
+(**************************************************************************)
+
+include "ground/relocation/pr_isi_pushs.ma".
+include "ground/relocation/pr_isu_uni.ma".
+include "ground/relocation/pr_coafter_uni_pushs.ma".
+
+(* RELATIONAL CO-COMPOSITION FOR PARTIAL RELOCATION MAPS ********************)
+
+(* Constructions with pr_isu and pr_isi *************************************)
+
+(*** coafter_isuni_isid *)
+lemma pr_coafter_isu_isi:
+ ∀f2. 𝐈❪f2❫ → ∀f1. 𝐔❪f1❫ → f1 ~⊚ f2 ≘ f2.
+#f #Hf #g #H
+elim (pr_isu_inv_uni … H) -H #n #H
+/5 width=4 by pr_isi_pushs, pr_isi_inv_eq_repl, pr_coafter_eq_repl_back, pr_coafter_eq_repl_back_sn/
+qed.