notational change of lift, drop, and gget

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / reduction / cnr.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/reduction/cnr.ma b/matita/matita/contribs/lambdadelta/basic_2/reduction/cnr.ma
index 26bb268eeca5689971b60527c318bb7ed773f577..c7064080846f8072912daaf70c694e7a6d5edad3 100644 (file)
--- a/matita/matita/contribs/lambdadelta/basic_2/reduction/cnr.ma
+++ b/matita/matita/contribs/lambdadelta/basic_2/reduction/cnr.ma
@@ -12,20 +12,20 @@
 (*                                                                        *)
 (**************************************************************************)
 
-include "basic_2/notation/relations/normal_3.ma".
+include "basic_2/notation/relations/prednormal_3.ma".
 include "basic_2/reduction/cpr.ma".
 
-(* CONTEXT-SENSITIVE NORMAL TERMS *******************************************)
+(* NORMAL TERMS FOR CONTEXT-SENSITIVE REDUCTION *****************************)
 
 definition cnr: relation3 genv lenv term ≝ λG,L. NF … (cpr G L) (eq …).
 
 interpretation
-   "context-sensitive normality (term)"
-   'Normal G L T = (cnr G L T).
+   "normality for context-sensitive reduction (term)"
+   'PRedNormal G L T = (cnr G L T).
 
 (* Basic inversion lemmas ***************************************************)
 
-lemma cnr_inv_delta: â\88\80G,L,K,V,i. â\87©[i] L ≡ K.ⓓV → ⦃G, L⦄ ⊢ ➡ 𝐍⦃#i⦄ → ⊥.
+lemma cnr_inv_delta: â\88\80G,L,K,V,i. â¬\87[i] L ≡ K.ⓓV → ⦃G, L⦄ ⊢ ➡ 𝐍⦃#i⦄ → ⊥.
 #G #L #K #V #i #HLK #H
 elim (lift_total V 0 (i+1)) #W #HVW
 lapply (H W ?) -H [ /3 width=6 by cpr_delta/ ] -HLK #H destruct
@@ -69,9 +69,9 @@ lemma cnr_inv_appl: ∀G,L,V,T. ⦃G, L⦄ ⊢ ➡ 𝐍⦃ⓐV.T⦄ → ∧∧ 
 ]
 qed-.
 
-lemma cnr_inv_tau: ∀G,L,V,T. ⦃G, L⦄ ⊢ ➡ 𝐍⦃ⓝV.T⦄ → ⊥.
+lemma cnr_inv_eps: ∀G,L,V,T. ⦃G, L⦄ ⊢ ➡ 𝐍⦃ⓝV.T⦄ → ⊥.
 #G #L #V #T #H lapply (H T ?) -H
-/2 width=4 by cpr_tau, discr_tpair_xy_y/
+/2 width=4 by cpr_eps, discr_tpair_xy_y/
 qed-.
 
 (* Basic properties *********************************************************)
@@ -82,6 +82,17 @@ lemma cnr_sort: ∀G,L,k. ⦃G, L⦄ ⊢ ➡ 𝐍⦃⋆k⦄.
 >(cpr_inv_sort1 … H) //
 qed.
 
+lemma cnr_lref_free: ∀G,L,i. |L| ≤ i → ⦃G, L⦄ ⊢ ➡ 𝐍⦃#i⦄.
+#G #L #i #Hi #X #H elim (cpr_inv_lref1 … H) -H // *
+#K #V1 #V2 #HLK lapply (drop_fwd_length_lt2 … HLK) -HLK
+#H elim (lt_refl_false i) /2 width=3 by lt_to_le_to_lt/
+qed.
+
+(* Basic_1: was only: nf2_csort_lref *)
+lemma cnr_lref_atom: ∀G,L,i. ⬇[i] L ≡ ⋆ → ⦃G, L⦄ ⊢ ➡ 𝐍⦃#i⦄.
+#G #L #i #HL @cnr_lref_free >(drop_fwd_length … HL) -HL //
+qed.
+
 (* Basic_1: was: nf2_abst *)
 lemma cnr_abst: ∀a,G,L,W,T. ⦃G, L⦄ ⊢ ➡ 𝐍⦃W⦄ → ⦃G, L.ⓛW⦄ ⊢ ➡ 𝐍⦃T⦄ → ⦃G, L⦄ ⊢ ➡ 𝐍⦃ⓛ{a}W.T⦄.
 #a #G #L #W #T #HW #HT #X #H