update in delayed_updating

[helm.git] / matita / matita / contribs / lambdadelta / delayed_updating / syntax / prototerm_eq.ma

diff --git a/matita/matita/contribs/lambdadelta/delayed_updating/syntax/prototerm_eq.ma b/matita/matita/contribs/lambdadelta/delayed_updating/syntax/prototerm_eq.ma
index baffe070a138b076ffa0a3965cc98ba7379543b8..5604578e52fa9839edb1a6ae9c6caf44344f5ebe 100644 (file)
--- a/matita/matita/contribs/lambdadelta/delayed_updating/syntax/prototerm_eq.ma
+++ b/matita/matita/contribs/lambdadelta/delayed_updating/syntax/prototerm_eq.ma
@@ -17,6 +17,13 @@ include "ground/lib/subset_equivalence.ma".
 
 (* EQUIVALENCE FOR PROTOTERM ************************************************)
 
+(* Constructions with prototerm_grafted *************************************)
+
+lemma grafted_empty_dx (t):
+      t ⇔ t⋔𝐞.
+/2 width=1 by conj/
+qed.
+
 (* Constructions with prototerm_root ****************************************)
 
 lemma prototerm_root_incl_repl: