- weakening leq, we proved cpr_bind_dx

[helm.git] / matita / matita / contribs / lambda-delta / Basic-2 / reduction / cpr.ma

diff --git a/matita/matita/contribs/lambda-delta/Basic-2/reduction/cpr.ma b/matita/matita/contribs/lambda-delta/Basic-2/reduction/cpr.ma
index f41999e45cf56f4e0772d48eb6e5653fdd110d0e..245cadff95e0a2280e094c3a829d0de6054d169c 100644 (file)
--- a/matita/matita/contribs/lambda-delta/Basic-2/reduction/cpr.ma
+++ b/matita/matita/contribs/lambda-delta/Basic-2/reduction/cpr.ma
@@ -34,6 +34,18 @@ lemma cpr_tps: ∀L,T1,T2,d,e. L ⊢ T1 [d, e] ≫ T2 → L ⊢ T1 ⇒ T2.
 lemma cpr_refl: ∀L,T. L ⊢ T ⇒ T.
 /2/ qed.
 
+lemma cpr_bind_sn: ∀I,L,V1,V2,T1,T2. L ⊢ V1 ⇒ V2 → T1 ⇒ T2 →
+                   L ⊢ 𝕓{I} V1. T1 ⇒ 𝕓{I} V2. T2.
+#I #L #V1 #V2 #T1 #T2 * /3 width=5/
+qed.
+
+lemma cpr_bind_dx: ∀I,L,V1,V2,T1,T2. V1 ⇒ V2 → L. 𝕓{I} V2 ⊢ T1 ⇒ T2 →
+                   L ⊢ 𝕓{I} V1. T1 ⇒ 𝕓{I} V2. T2.
+#I #L #V1 #V2 #T1 #T2 #HV12 * #T #HT1 normalize #HT2
+elim (tps_split_up … HT2 1 ? ?) -HT2 // #T0 <minus_n_O #HT0 normalize <minus_plus_m_m #HT02
+lapply (tps_leq_repl … HT0 (⋆. 𝕓{I} V2) ?) -HT0 /2/ #HT0 /3 width=5/
+qed.
+
 (* NOTE: new property *)
 lemma cpr_flat: ∀I,L,V1,V2,T1,T2.
                 L ⊢ V1 ⇒ V2 → L ⊢ T1 ⇒ T2 → L ⊢ 𝕗{I} V1. T1 ⇒ 𝕗{I} V2. T2.