milestone in basic_2

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / substitution / lpss.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/substitution/lpss.ma b/matita/matita/contribs/lambdadelta/basic_2/substitution/lpss.ma
index d440960f1a62fb914b556de5859eb6ecaa772ec1..0c806c49fb06f2fad4663dbf60c23cef9cd39479 100644 (file)
--- a/matita/matita/contribs/lambdadelta/basic_2/substitution/lpss.ma
+++ b/matita/matita/contribs/lambdadelta/basic_2/substitution/lpss.ma
@@ -12,7 +12,7 @@
 (*                                                                        *)
 (**************************************************************************)
 
-include "basic_2/grammar/lenv_px_sn.ma".
+include "basic_2/grammar/lpx_sn.ma".
 include "basic_2/substitution/cpss.ma".
 
 (* SN PARALLEL SUBSTITUTION FOR LOCAL ENVIRONMENTS **************************)
@@ -45,6 +45,10 @@ lemma lpss_inv_pair2: ∀I,L1,K2,V2. L1 ⊢ ▶* K2. ⓑ{I} V2 →
 lemma lpss_refl: ∀L. L ⊢ ▶* L.
 /2 width=1 by lpx_sn_refl/ qed.
 
+lemma lpss_pair: ∀I,K1,K2,V1,V2. K1 ⊢ ▶* K2 → K1 ⊢ V1 ▶* V2 →
+                 K1.ⓑ{I}V1 ⊢ ▶* K2.ⓑ{I}V2.
+/2 width=1/ qed.
+
 lemma lpss_append: ∀K1,K2. K1 ⊢ ▶* K2 → ∀L1,L2. L1 ⊢ ▶* L2 →
                     L1 @@ K1 ⊢ ▶* L2 @@ K2.
 /3 width=1 by lpx_sn_append, cpss_append/ qed.