+++ /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 "basic_2/unfold/ltpss_sn.ma".
-
-(* BASIC LOCAL ENVIRONMENT THINNING *****************************************)
-
-definition thin: nat → nat → relation lenv ≝
- λd,e,L1,L2. ∃∃L. L1 ⊢ ▶* [d, e] L & ⇩[d, e] L ≡ L2.
-
-interpretation "basic thinning (local environment)"
- 'TSubst L1 d e L2 = (thin d e L1 L2).
-
-(* Basic properties *********************************************************)
-
-lemma ldrop_thin: ∀L1,L2,d,e. ⇩[d, e] L1 ≡ L2 → ▼*[d, e] L1 ≡ L2.
-/2 width=3/ qed.
-
-(* Basic inversion lemmas ***************************************************)
-
-lemma thin_inv_thin1: ∀I,K1,V1,L2,e. ▼*[0, e] K1.ⓑ{I} V1 ≡ L2 → 0 < e →
- ▼*[0, e - 1] K1 ≡ L2.
-#I #K1 #V1 #L2 #e * #X #HK1 #HL2 #e
-elim (ltpss_sn_inv_tpss21 … HK1 ?) -HK1 // #K #V #HK1 #_ #H destruct
-lapply (ldrop_inv_ldrop1 … HL2 ?) -HL2 // /2 width=3/
-qed-.