-(**************************************************************************)
-(* ___ *)
-(* ||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 "basic_2/unfold/gr2.ma".
-
-(* GENERIC RELOCATION WITH PAIRS ********************************************)
-
-let rec pluss (des:list2 nat nat) (i:nat) on des ≝ match des with
-[ nil2 ⇒ ⟠
-| cons2 d e des ⇒ {d + i, e} @ pluss des i
-].
-
-interpretation "plus (generic relocation with pairs)"
- 'plus x y = (pluss x y).
-
-(* Basic inversion lemmas ***************************************************)
-
-lemma pluss_inv_nil2: ∀i,des. des + i = ⟠ → des = ⟠.
-#i * // normalize
-#d #e #des #H destruct
-qed.
-
-lemma pluss_inv_cons2: ∀i,d,e,des2,des. des + i = {d, e} @ des2 →
- ∃∃des1. des1 + i = des2 & des = {d - i, e} @ des1.
-#i #d #e #des2 * normalize
-[ #H destruct
-| #d1 #e1 #des1 #H destruct /2 width=3/
-]
-qed-.