+++ /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 "lambda/ext.ma".
-include "lambda/subst.ma".
-
-(* MATTER CONCERNING STRONG NORMALIZATION TO BE PUT ELSEWHERE *****************)
-
-(* substitution ***************************************************************)
-(*
-axiom is_dummy_lift: ∀p,t,k. is_dummy (lift t k p) = is_dummy t.
-*)
-(* FG: do we need this?
-definition lift0 ≝ λp,k,M . lift M p k. (**) (* remove definition *)
-
-lemma lift_appl: ∀p,k,l,F. lift (Appl F l) p k =
- Appl (lift F p k) (map … (lift0 p k) l).
-#p #k #l (elim l) -l /2/ #A #D #IHl #F >IHl //
-qed.
-*)
-(*
-lemma lift_rel_lt: ∀i,p,k. (S i) ≤ k → lift (Rel i) k p = Rel i.
-#i #p #k #Hik normalize >(le_to_leb_true … Hik) //
-qed.
-*)
-lemma lift_rel_not_le: ∀i,p,k. (S i) ≰ k → lift (Rel i) k p = Rel (i+p).
-#i #p #k #Hik normalize >(lt_to_leb_false (S i) k) /2/
-qed.
-
-lemma lift_app: ∀M,N,k,p.
- lift (App M N) k p = App (lift M k p) (lift N k p).
-// qed.
-
-lemma lift_lambda: ∀N,M,k,p. lift (Lambda N M) k p =
- Lambda (lift N k p) (lift M (k + 1) p).
-// qed.
-
-lemma lift_prod: ∀N,M,k,p.
- lift (Prod N M) k p = Prod (lift N k p) (lift M (k + 1) p).
-// qed.
-
-lemma subst_app: ∀M,N,k,L. (App M N)[k≝L] = App M[k≝L] N[k≝L].
-// qed.
-
-lemma subst_lambda: ∀N,M,k,L. (Lambda N M)[k≝L] = Lambda N[k≝L] M[k+1≝L].
-// qed.
-
-lemma subst_prod: ∀N,M,k,L. (Prod N M)[k≝L] = Prod N[k≝L] M[k+1≝L].
-// qed.
-
-
-axiom lift_subst_lt: ∀A,B,i,j,k. lift (B[j≝A]) (j+k) i =
- (lift B (j+k+1) i)[j≝lift A k i].
-
-(* telescopic delifting substitution of l in M.
- * Rel 0 is replaced with the head of l
- *)
-let rec tsubst M l on l ≝ match l with
- [ nil ⇒ M
- | cons A D ⇒ (tsubst M[0≝A] D)
- ].
-
-interpretation "telescopic substitution" 'Subst M l = (tsubst M l).
-
-lemma tsubst_refl: ∀l,t. (lift t 0 (|l|))[/l] = t.
-#l elim l -l; normalize // #hd #tl #IHl #t cut (S (|tl|) = |tl| + 1) // (**) (* eliminate cut *)
-qed.
-
-lemma tsubst_sort: ∀n,l. (Sort n)[/l] = Sort n.
-// qed.