update in basic_2

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / static / lfxs_fle.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/static/lfxs_fle.ma b/matita/matita/contribs/lambdadelta/basic_2/static/lfxs_fle.ma
index 0d851ce6a9626a29052fcff4fd86c4657296d642..cc067e50ae7ac5668174a7149b79b8189b688a03 100644 (file)
--- a/matita/matita/contribs/lambdadelta/basic_2/static/lfxs_fle.ma
+++ b/matita/matita/contribs/lambdadelta/basic_2/static/lfxs_fle.ma
@@ -12,6 +12,7 @@
 (*                                                                        *)
 (**************************************************************************)
 
+include "basic_2/syntax/lveq_length.ma".
 include "basic_2/static/fle.ma".
 include "basic_2/static/lfxs_lfxs.ma".
 
@@ -19,8 +20,10 @@ include "basic_2/static/lfxs_lfxs.ma".
 
 (* Properties with free variables inclusion for restricted closures *********)
 
+(* Note: we just need lveq_inv_refl: ∀L,n1,n2. L ≋ⓧ*[n1, n2] L → ∧∧ 0 = n1 & 0 = n2 *)
 lemma fle_lfxs_trans: ∀R,L1,T1,T2. ⦃L1, T1⦄ ⊆ ⦃L1, T2⦄ →
                       ∀L2. L1 ⪤*[R, T2] L2 → L1 ⪤*[R, T1] L2.
-#R #L1 #T1 #T2 * #f1 #f2 #Hf1 #Hf2 #Hf12 #L2 #HL12
+#R #L1 #T1 #T2 * #n1 #n2 #f1 #f2 #Hf1 #Hf2 #Hn #Hf #L2 #HL12
+elim (lveq_inj_length … Hn ?) // #H1 #H2 destruct
 /4 width=5 by lfxs_inv_frees, sle_lexs_trans, ex2_intro/
 qed-.