--- /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/notation/relations/lazypredsn_5.ma".
+include "basic_2/relocation/llpx_sn.ma".
+include "basic_2/reduction/cpr.ma".
+
+(* LAZY SN PARALLEL REDUCTION FOR LOCAL ENVIRONMENTS ************************)
+
+definition llpr: genv → relation4 ynat term lenv lenv ≝ λG. llpx_sn (cpr G).
+
+interpretation "lazy parallel reduction (local environment, sn variant)"
+ 'LazyPRedSn G L1 L2 T d = (llpr G d T L1 L2).
+
+(* Basic inversion lemmas ***************************************************)
+
+lemma llpr_inv_flat: ∀I,G,L1,L2,V,T,d. ⦃G, L1⦄ ⊢ ➡[ⓕ{I}V.T, d] L2 →
+ ⦃G, L1⦄ ⊢ ➡[V, d] L2 ∧ ⦃G, L1⦄ ⊢ ➡[T, d] L2.
+/2 width=2 by llpx_sn_inv_flat/ qed-.
+
+(* Basic forward lemmas *****************************************************)
+
+lemma llpr_fwd_length: ∀G,L1,L2,T,d. ⦃G, L1⦄ ⊢ ➡[T, d] L2 → |L1| = |L2|.
+/2 width=4 by llpx_sn_fwd_length/ qed-.
+
+(* Basic properties *********************************************************)
+
+lemma llpr_lref: ∀I,G,L1,L2,K1,K2,V1,V2,d,i. d ≤ yinj i →
+ ⇩[i] L1 ≡ K1.ⓑ{I}V1 → ⇩[i] L2 ≡ K2.ⓑ{I}V2 →
+ ⦃G, K1⦄ ⊢ ➡[V1, 0] K2 → ⦃G, K1⦄ ⊢ V1 ➡ V2 → ⦃G, L1⦄ ⊢ ➡[#i, d] L2.
+/2 width=9 by llpx_sn_lref/ qed.
+
+(* Note: lemma 250 *)
+lemma llpr_refl: ∀G,T,d. reflexive … (llpr G d T).
+/2 width=1 by llpx_sn_refl/ qed.
+
+(* Basic_1: removed theorems 5: wcpr0_gen_sort wcpr0_gen_head
+ wcpr0_getl wcpr0_getl_back
+ pr0_subst1_back
+*)