severe bug found in parallel zeta

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / dynamic / cnv.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/dynamic/cnv.ma b/matita/matita/contribs/lambdadelta/basic_2/dynamic/cnv.ma
index 97c1feca2ff0271bf2794c13797b2a8ee76b5799..bde05a33cabcc6d4ee858568f74563abdaeb164d 100644 (file)
--- a/matita/matita/contribs/lambdadelta/basic_2/dynamic/cnv.ma
+++ b/matita/matita/contribs/lambdadelta/basic_2/dynamic/cnv.ma
@@ -140,6 +140,17 @@ lemma cnv_inv_cast (a) (h): ∀G,L,U,T. ⦃G, L⦄ ⊢ ⓝU.T ![a, h] →
                                   ⦃G, L⦄ ⊢ U ➡*[h] U0 & ⦃G, L⦄ ⊢ T ➡*[1, h] U0.
 /2 width=3 by cnv_inv_cast_aux/ qed-.
 
+(* Basic forward lemmas *****************************************************)
+
+lemma cnv_fwd_flat (a) (h) (I) (G) (L):
+                   ∀V,T. ⦃G, L⦄ ⊢ ⓕ{I}V.T ![a,h] →
+                   ∧∧ ⦃G, L⦄ ⊢ V ![a,h] & ⦃G, L⦄ ⊢ T ![a,h].
+#a #h * #G #L #V #T #H
+[ elim (cnv_inv_appl … H) #n #p #W #U #_ #HV #HT #_ #_
+| elim (cnv_inv_cast … H) #U #HV #HT #_ #_
+] -H /2 width=1 by conj/
+qed-.
+
 (* Basic_2A1: removed theorems 6:
               snv_fwd_da snv_fwd_lstas snv_cast_scpes
               shnv_cast shnv_inv_cast snv_shnv_cast